I too am using an 8+ I purchased new (Apple refurbished) a few months ago.
1. It’s definitely not slow (still on iOS 14)
2. Camera is better than what I need.
3. It’s the best form factor ever
4. No notch
5. No Flickering.
6. Good speakers.
7. Fast Touch ID
There’s nothing I can fault this phone for. As far as I’m concerned, it is a “flagship“.
If you want to experience real frustration, use an iPhone 6+ for a while. Geezus that thing is brutal.
Spittin facts, as far as I'm concerned the 8+ is the best phone Apple's ever made. Mine's on 15.5 beta and it still flies. It'll probably still be my main even with the new SE, I'll use that when I need to save space in my purse but for daily use the 8+ really is perfect.