[One (M9) Q&A, Help & Troubleshooting] Myrmeko:
For that price and just to play around with it, totally.

But the first thing you should do if you get one would be to go to a service, open it up and clean the dust from the speaker grille.

Or try at home with a toothbrush and a vacuum cleaner. (This is what i personally do, but there is clearly still dust in there because the sound is still cracking at high volume. Plus, dust particles still fly away from the speaker, even after cleaning, if i turn the volume all the way up)

But if you clean it professionally, it has an incredible speaker setup.

Camera now. The Nougat 7.0 update made the camwra usable in low light. (You could try to find the link for SunDream's 7.1.2 S.ROM because is clearly the best Sense-based ROM around here. And also the only one that also raised the API level by 1 over the OTA limit.)

Like, is incredible how much right that one update did... But you lose the 9 seconds of exposure time from the "More Light More Fun" Mod (or something between those lines. Somebody posted the link in this thread anyway).

Anyway, (5.1.1 MLMF + Luma Denoise. What i currently use) in daytime and slightly less than perfect light conditions, the camera performs really good.

The bokeh effect is amazing, like the edge detection is on point. It detects those hair strings like magic.

I did a bokeh test on a moving pine tree branch, and it got all the pins right.

Not a single one got blurred over.

I tried it against the Note 8, the S9+ and the iPhone X (stuff that my classmates have) and beat all of them at edge detection from my personal tests.

The others struggle with reflective surfaces from what i observed.

Anyway, performance.

Good. Doesnt slow down over time.

Never cleaned dalvik, never zipaligned, never optimized databases, never installed a new ROM.

I challenged myself to use it with what it had installed (in my case, the update right before 6.0.1).

It can still play PUBG just fine on HD settings... For like 10 minutes because it heats up and throttles.

But older games work just fine on the highest settings.

Screen. If you can ignore the fact that black is some sort of very dark blue, is ok.

You can play VR with it just fine. You wont notice the pixels.

Also, if you set it on Automatic, it actually goes darker than the lowest brightness setting.

(Also, activating the brightness slider from the customization file still doesnt make it darker than Auto Brightness.)

IR is really useful, imo.

Headphone sound was really good for it's time, but it's still just a 24-bit DAC.

Bluetooth is just AptX and you can feel the compression.

But still enjoyable with Viper FX.

I think you can patch AptX HD tho...

Also if i remeber correctly there is a mod that makes the speakers louder.

And finally Dolby Digital Surround 5.1 is very realistic... If the speakers are clean.

Done. Would i recommend it in 2018?

As a secondary phone, totally.

Would a Butterfly 3 be better? Obviously, if you dont care that much about ROMs and customization. (It has water resistance and dual cameras.)

So... For 60$. Have fun. Install as many ROMs you want.

(Also a good time to buy one because MIUI finally got released, so you have a very wide sellection of ROMs.)