Personally, I use both methods, usually shifting preference depending on the game - KB/mouse more for first person or RPGs with GCD, but controllers for third person action, that sort of thing. In my own experience, I haven't really run across problems with tracking speed.
That being said, a quick Google shows that plenty of people
have, at least in some titles.
For Steam particularly, you have the potential for in-depth controller configuration via Big Picture mode. The
upside to this is that you can use that to create a custom controller profile and tweak how it works to suit you. The potential (albeit rare, I think) problem can be if Steam uses it when it's not needed. If it does that and maps the left stick to mouse input (or whatever) it can end up being too sensitive. Might be something people ran into more when it was in beta though. (there's similar functionality in
https://www.rewasd.com/ for general use). MS lets you do similar stuff with official software, but only for the Elite controller.
Some games literally seem to do that anyway, so adjusting mouse sensitivity may adjust aiming speed too. Or there may be ways to change it, whether built into the game or via config files or whatnot.
Could partly be the game, as I know
Andromeda had a ton of complaints about the controller implementation on all platforms.
Might also be other factors to it, since if I recall you make a point to play at low framerate, and choppiness doesn't help aiming.
