Here are my personal remarks on the construction of a typical Seimitsu LS-series joystick, the LS-40-01, versus the Sanwa standard JLF. These are observations of one individual, not absolute facts!
As a general rule, I prefer the performance of LS-series joysticks to the Sanwa JLF.
The JLF has serious peformance design issues and shortcomings, folks, or there wouldn't be a huge aftermarket for customizing the Sanwa JLF out the whazoo! That's the reality I perceive.
That said, I wouldn't trade my grandmother (if I had a living one) in for spare parts if I lost screws on an LS-series joystick because damn those LS-controllers are built with so many screws! I gotta hand it to Sanwa – they engineered and built a joystick with very few parts that slides together gracefully and is held together solely by the clamps that plug into the restrictor gate at the bottom of the unit. To fully disassemble an LS-series joysticks, I'm looking at removing at least 10 screws – and you have to remove those screws to take off the the restrictor gate(s) and microswitch assembly every time you want to install an LS joystick in a case! So far, I've NEVER had to disassemble a JLF to completely remove it OR install it (which ain't happening for as long as I'm playing, fellows).
For all that admittedly nitpicking inconvenience, I'd still take an LS-series joystick (LS-32 or LS-40, for sure!) over a Sanwa JLF any day of the week. The JLF has a long throw which means it takes longer to activate its microswitches and you have to move the stick way faster and over a longer distance to hit those tiny microtabs! As a consequence, I don't think it's a particularly great joystick for any pre-2009 Capcom fighter (which is well over 90% of their catalog on CPS-1/-2/-3 machines) and even on the polygon fighters where speed may not be as crucial I found that the LS joysticks were just more comfortable and more to my tastes. The shorter throw, faster recentering, and generally greater ease of using a square gate on the LS-joysticks isn't something to be sneezed at. Even on alternate retro-genre games, I find the LS-joysticks to be more comfortable and suitable for play. It's been widely banded about on the forums for side-scrolling retroshooters and platform games (ie, Donkey Kong) and crossovers into the SRK/fighting game forums that an LS-32 or LS-56 is preferrable to the Sanwa JLF for playing many games. The JLF simply can't beat the response time and accuracy of an LS-joystick.
To illustrate some of my points, I took photos of two sample controllers, Sanwa JLF on the left and Seimitsu LS-40-01 on the right. http://support.paradisearcadeshop.net/lib/exe/fetch.php?media=img_0145.jpg
There isn't a terrific difference in size, but the first photo is kind of deceiving because of elevation difficulties in photography. In truth, the RE: Flat Mounting Plate on the LS-40 is shorter than the JLF's mounting plate. Likewise, the LS-40 is actually a bit bulkier and taller as a stack than the JLF. The shaft on the JLF is actually longer than the LS-40. The Flat Mounting Plate is not ideal for mounting an LS-40 into a joystick – you'd really want to replace it with an SS Mounting Plate to get a more comfortable height above the faceplate –, BUT it's what comes standard with the LS-40 despite the fact at least 95% of us eventually install LS-40s into home joystick cases with the SS Mounting Plate! (Okay, that's nitpick infinity about Seimitsu practices but moving further on…!) http://support.paradisearcadeshop.net/lib/exe/fetch.php?media=img_0146.jpg
Here's what the two joysticks look like with the balltop handles removed. Not much difference, really… The JLF on the left comes standard with two dustcovers – one for above the faceplate, and one for just underneath. They do the maximum job of keeping dust from collecting into the pivot. Seimitsu joysticks like the LS-40 only come with one standard dustcover. Those LS-joysticks that mount with SS-Mounting Plates (LS-32, LS-40) just don't have the clearance room for a second dustcover UNLESS you use a custom-mounting situation in a non-universal joystick case… (That's short English for creating a “universal” mount in a non-universal joystick like Hori's Tekken 5/US 10th Anniversary Edition by drilling out the old joystick mount and hanging the replacement control lever from newly drilled in screws. That situation is ideal for a flat mounting plate AND clearance is there for a second dustcover… The Sanwa dustcover for shaft covers works just fine here!) http://support.paradisearcadeshop.net/lib/exe/fetch.php?media=img_0147.jpg
Pictured here is a Sanwa JLF completely disassembled short of removing the mounting plate. As much as I don't like how the joystick performs, the JLF is a very fine piece of design engineering with minimal hardware and not much screwdriver work required. Here, you can clearly see the red microtabs on the PCB substrate. In my opinion, this is the biggest downfall of the design. You have to move too far to hit microtabs that are arguably a bit too tight for the design. http://support.paradisearcadeshop.net/lib/exe/fetch.php?media=img_0148.jpg
Here's the bottom of the Seimitsu LS-40-01 pictured just before removal of the first restrictor gate. I'd argue that one of the stronger design features of the Seimitsu LS-joysticks are their restrictor gates. They're just better than the JLF's, period. That said, I have to say I generally prefer the blue restrictor gate that ships with the LS-32 to the LS-40's yellow gate. The four-way restrictor definitely works better on the LS-32. http://support.paradisearcadeshop.net/lib/exe/fetch.php?media=img_0151.jpg
The main white restrictor gate of the LS-40 is exposed with removal of the yellow gate. Not much difference amongst the LS-series joystick designs here… http://support.paradisearcadeshop.net/lib/exe/fetch.php?t=1380255860&w=500&h=375&tok=bc49d3&media=img_0153.jpg
The PCB substrate of the LS-40 is exposed. Aha! We're getting closer to why I ultimately feel the LS-series joysticks perform better than the JLF. Note one design feature here – the circuitry pattern points downward on the LS-series joysticks whereas it orients up towards the mounting plate on the JLF! Just a minor bit of trivia here. http://support.paradisearcadeshop.net/lib/exe/fetch.php?t=1380255872&w=500&h=375&tok=8da5e9&media=img_0154.jpg
The LS-40 with the PCB substrate removed and flipped exposing the gated microswitches. Those gates are the primary reason I think the LS-series joysticks perform better. The gates act as a lever on the microtabs enabling faster microswitch activation on the joystick. I also believe the gates enable easier use of the square restrictor gates on the LS-joysticks. It's so easy to do rolling and circular motions on an LS-joystick. I never got much past half-circular motions on a JLF and even those are more comfortable on an LS-joystick. People usually resort to using Octagonal gates on the JLF but I think those are a crutch. No matter how much I ratcheted up the tension, I never got the best recentering, charging, or consistent circulars on the JLF. I think in the long run it's both far less annoying and cheaper to replace the JLF with a more comfortable joystick than to futz with a million mod parts as if the damn hardware were some hot rod! http://support.paradisearcadeshop.net/lib/exe/fetch.php?t=1380255875&w=500&h=375&tok=031cc3&media=img_0155.jpg
Here's a comparison view of the PCB microswitches from the JLF (left) and the LS-40-01 (right). I'm convinced that after 3+ years of playing with LS-32's and LS-40's that the Seimitsu PCB/microswitch is superior to the Sanwa JLF's. If that weren't the case, again I ask – why such a big after-market to “improve the perfect joystick (Sanwa JLF)?” http://support.paradisearcadeshop.net/lib/exe/fetch.php?t=1380255886&w=500&h=375&tok=87112a&media=img_0157.jpg