Just used it for a couple hour. My tempered glass SP is still not yet here so keep factory screen sticker on for now.
I changing phone from HTC One M8 so this Flash Plus 2 got a lot of expectation to fill.
First impression, build quality is quite good. There is some minor finishing not proper on my headphone jack but that's it as far as I can tell.
Home button is kinda stiff, but it's not an issue.
The rear speaker is good. Well as good as a rear speaker can be since my old HTC got front facing boomsound. An issue might surface when one put the phone inside pocket and the speaker could get muffled.
Fingerprint reader is FAST and quite accurate (not as accurate as my friends Vivo V3 Max but still good and just as fast!) Do note that the fingerprint reader doesnt work when the screen is off.
Double tap to wake! (this feature was used a lot on my HTC)
The UI is very close to vanilla android. Love it. Surprisingly there's very few bloatware on this phone.
Camera, well it's shit in low light. (my HTC got ultrapixel duo camera so i might be asking too much)
Overall I dont regret purchasing this phone. Anything you guys want to know or test just tag me ya.
Edit:
Headphone sound quality, i used my HTC headphones(these can deliver really good quality) to test, and it doesnt disappoint. Audio is loud and clear to me.