A good example: their SN30 Pro has a bad bluetooth chip in it that makes Xinput support really laggy (I don't know the specifics). It's been years now, and had a few firmware updates, but there's still been no fix. It works great for everything else though, so I still keep it around.
Just a warning for anyone thinking of buying one after reading this...
On a good day, yeah, I have 100Mb upload so I could just match that going full ham. But I mainly seed rare (<10 seeds) things now and set a 10.0 ratio cap on all of the new/popular stuff. Gotta keep those '80s and '90s ISOs seeded, ya know? ;)