Pwll: Probably mostly just random ranges, multiway pots and people floating with anything they played preflop with which makes it harder to put them on anything reasonable. I've had exactly the same trouble with this game, not that I'm playing much; I am winning, it just doesn't feel like it sometimes! ;)
Yeh I'm used to making lots of notes so I know what players are limp-calling, or calling 3bets with, but on 888 Snap it's more difficult to do that. I've started 4x opening UTG as I'm getting a lot of calls from CO and BTN. Also 2.5xing the button which seems to get more folds than min raising.