I absolutely love mine. I'm coming from an iPhone X, and I forgot how much I missed the bigger screen. Some apps look a little *too* large right now, but not in that blown-out way that old iPhone 6 Plus apps did back on the original release when devs hadn't optimized yet.
Took it for a trail run this morning with my new S4 watch (I use a FlipBelt for my phone when I'm not running w/a pack) -- GPS was dead on, everything worked beautifully.
I did have "quirks" going from S0 to S4 watch where the restore from backup was a bit buggy, but after resetting the S4 to new, it's perfectly fine. Same w/restoring from backup of iPhone X -- in Settings, I couldn't search, etc. Did a Reset all settings (which keeps your data but wipes all your settings) and that fixed it.
Now everything's dialed in and working like a charm.
Think I'm gonna keep this one for the full two years at least -- it's everything I was looking for in a phone -- fast LTE, great camera, beautiful big screen, gorgeous gold color, etc 
Took it for a trail run this morning with my new S4 watch (I use a FlipBelt for my phone when I'm not running w/a pack) -- GPS was dead on, everything worked beautifully.
I did have "quirks" going from S0 to S4 watch where the restore from backup was a bit buggy, but after resetting the S4 to new, it's perfectly fine. Same w/restoring from backup of iPhone X -- in Settings, I couldn't search, etc. Did a Reset all settings (which keeps your data but wipes all your settings) and that fixed it.
Now everything's dialed in and working like a charm.