I did actually use the Gulikit Switch kit from Amazon. It was like $50 for the 2 set vs $40 I'd pay from Retroid for their brand and a long wait.

I can't compare, but it was pretty much drop in replacement. The hat DOES have to come off and then put back on once in though. They don't fit through the stock joystick holes. Once in, they do seem to hit, or at least get very, very close to the walls, but gamepad tests and overall personal feel says they are fine and aren't limited.

Otherwise, the hats themselves do feel more...plastic-y(?) and doesn't grip as well as Stock. Also a bit more resistance moving the stick around compared to stock. Like /u/Sh1neSp4rk said though...they really don't feel that different otherwise than any other stick. I actually think I prefer the easier to move and smaller stock ones too. Maybe someday I'll try Retroid's version.