I bought one of these
USB recreations of the Sega Saturn pad. It's garbage.
I never realized this before, but the reason the Saturn pad is so damn great for shooters and such is that it's extremely responsive to tapping on the directionals. Want to nudge your ship left the slightest bit? Tap left for a few milliseconds, and the pad will translate your physical input into exactly the movement you wanted onscreen. This sounds kind of obvious and is something I guess I took for granted. Unfortunately, the USB Saturn clone is not half as responsive. Not a fourth.
Sure, it looks like a Saturn pad. It even feels like one, at least in your hands. However, as soon as I tried it in a game (doujin shooter ChoRenSha 68k, then rRootage) I noticed what seemed like a strange lag in my ship's movement. It almost seemed like some inputs weren't being read. After some experimentation, it turns out that's exactly the case. The USB Saturn pad requires some serious travel distance before it deigns your input worthy of being sent to the PC. As a result, you can tap the thing's d-pad all day and not see a lick of movement onscreen. You need to push the pad fully and firmly in the desired direction -- only then will it actually, you know, work.
I doubt this is software / driver/ USB-related; it's almost certainly a serious physical flaw in the d-pad's design. Assuming this isn't merely a bad instance of this controller (bad luck for me, then), the company that made it didn't recreate Sega's winning controller design with a high degree of accuracy. Oh, it looks the part. But it certainly doesn't play it. Buyer beware.