I've had a GS2, GS4, GS5, and my wife had a Note3/
We just recently bought Asus' Zenphone Laser3. Thus far I've noticed that performs just as well as any other phone I've had, with the extra features of Android 6. It also gets *much* better battery life than any Samsung I've ever owned. At $270CAD, it's significantly cheaper than the major Samsung models, but has better specs than their "cheap" models (e.g. better CPU, 32GB instead of 8GB storage), and comes factory unlocked (with none of that lock-to-the-first-SIM-card-used BS either).
The only downside I've seen to it thus far is that it doesn't have a removable battery like the ZF2 had, lacks wireless charging (Asus: PLEASE add this to the next model), and you can't have a second SIM card if you want to use a MicroSD.
Least to say, I don't see myself with any need to buy an S8 or any other Samsung. The more recent models already did away with removable batteries and don't support dual-SIM, so the only advantage they seem to have is the wireless charging. While I do love the charging, it's not a feature that I'm willing to pay double the price for nor submit myself to Samsung's dearth of updates for any non-current device.