I've played on both but have had better success on Bovada.
ACR-
Pros: Better software, their own version of spin n go, eligible for rake back deals, more FR action.
Cons: Low tournament and SNG volume, no "zone, zoom, or rush" style games, linked to a screen name.
Pro or Con depending on your style/view: Many "extra long" late reg of 3-5 hours with rebuy and add on, so very very long tourneys. Static tables only.
Bovada -
Pros: More fish as it's a sports betting site with poker instead of a
poker site with some sports betting, Zone Poker, more traffic in general esp in tournaments,
Cons: Software is glitchy lately and crashes/freezes at times, bet buttons/slider isn't very precise, No rake back allowed.
Pros/Cons depending on your style/view: Good points system to redeem for tourney or SNG tickets, Anonymous play which limits use of HUDs, limits getting reads/notes but attracts more and more fish I think.
I played for longer on ACR (under the BCP banner) but have easier had much more success on Bovada.