I rarely use a case, and so I'll likely go "naked" on the 7+. That's what AC+ is for anyways, and so far **knocks on the faux wood desk at work** I've been pretty fortunate to not have a nasty drop. I hate screen protectors, and aside from the micro scratches in the oleophobic coating, the screens seem to hold up pretty well, and I've not had problems with scratching. There's a first time for everything though, and AC+ gives me the peace of mind I need to not use a case.
On my 6S+ I used the woodline cases from Pad & Quill, and liked them quite a bit. Eventually, I take them off and just don't put them back on. If I could have my money back for every case I've bought, used until the return period was up, and then stopped using, I could probably pay for a substantial portion of the 7+ I pre-ordered...