I have taken it upon myself to try as many different stands around town that sell this ice cream so I can tell you which one to try. It's pretty rough here in Guadalajara.
We tried the original store of Nieves de Garrafa Mexicaltzingo's on Thursday and neither of us were impressed. I've been trying coconut at all the places so I can compare them easily and it was full of dried coconut and really didn't have that great of flavor or texture. We won't bother with them again.
Today we tried Nieves de Garrafa San Antonio in Plaza Mexico and it was definitely better than Mexicaltzingo, but not as good as Chapalita. I won't seek it out, but if that's what's available, I'd try it again.
We've also been to the original location for Nieves de Garrada Chapilta and it's still the best. Also, there's a crepes place, a juice place, and a tacos al pastor place all on the same corner with lots of seating, so who could ask for anything more?
There's also Nieves de Garrada Jocotepec, La Deliciosa, and lots of non-chain places. There's lots of work to do.