I also bought the 8bitdo M30, which mimics the 6 button controller for the Sega Genesis. I also wish that it had analogue L & R buttons for consoles that benefit from incremental values to their L&R buttons instead of just on or off.
#Inputmapper ds4 latency pro
They still feel fine, but I do wish they were slightly better. I read that the Pro + has improved components, but that's according to the manufacturer, so I'd be curious to see if anyone else has tested it. To be fair, I'm not sure most people would really notice, but people reading a message board on the subject of controller recommendations for emulation are going to be a bit more discerning than your average gamer.
Not that I've had any problem with them, but after a few weeks, they lost a bit of the smooth quality. The only problem I have with the SF30/SN30 Pro is that, after a bit of wear-in time, the d-pad, analogue sticks, and X/Y/A/B buttons become *slightly* stiff. I just watched this review of it, and the guy who tested it said that it has 44 ms of lag via USB, which is the same as the X-Box One controller, and 64ms via Bluetooth, which he claims is among the best he's tested. They just released a new model, called the SN30 Pro+, which has some software that lets you customize some aspects of it. To add onto what everyone else has said, I'm currently using the 8bitdo SF30 Pro controller (I also have the SN30, same thing, but with SNES style buttons), and find that it works wonderfully for balancing between a retro feel with modern functionality.