no it's not tacky, but I think it's important to read the room as well - i like to print notes as well, but I've found that at some ACs, people tend to be more social rather than studying up on their notes etc. so if you're the only person who's isolating themselves during a break etc to read your notes, then that might not come across very well.
what I like to do is go to the toilet with my bag and quickly skim the notes there... lol
but other firms might let you look over notes or keep you in more of a quiet atmosphere between stages, and I think it's fine to look over your notes in those instances