I did, via an S8+. I had an iPhone 6 Plus since release day and moved to an S8+ a few months ago but while I love the hardware and to quite an extent I really enjoyed Android, I just missed iOS too much. I picked up an iPhone 8 Plus a few days ago and I'm enjoying it. Partly because it's so good to be back on iOS, but all the little additions since the iPhone 6 have made it feel more of a substantial change. Granted, I've lost out on a few things from the S8+ but I haven't lost anything I actually care about so it's a change that works for me...though I may end up keeping the S8+ anyway as my work phone
It's a shame that the iPhone 8's design isn't any different but I can live with that (or I'd have waited for the X). However, it's the first iPhone since the iPhone 6 that's worthy of a jump up in my opinion. First thing that strikes you is that it's a LOT faster. The screen somehow seems to be better - I can't put my finger on exactly how but it's certainly nicer than my 6 is after having the two side-by-side. Battery life is quite a bit better too but obviously with my iPhone 6 now being 3 years old the battery has suffered since it was new. It's really nice to finally have wireless charging on an iPhone, too.
I realise you're talking about the regular devices rather than the Plus but it should still all pretty much hold up.