Long time iPhone user who just converted to Android with the Nexus 5X and honestly, this phone isn't meeting my expectations. I love the size, the fingerprint sensor is friggin so fast - way faster than Apple, but this phone feels underpowered.
The camera is so sluggish you will miss photos if you're not ready and posing for them. I hope this is a software issue and not an issue with the phone being underpowered. Shooting video is even worse....
I've also experienced overall system slowdown, app sluggishness. Just this week I was streaming spotify to a bluetooth speaker and bouncing back and forth between a couple apps, nothing too intensive, and the phone ground to a halt. The music even started sputtering for a couple minutes. I had to power cycle the phone to get things back to normal.
So far I am happy with the flexibility of Android, love the Google ecosystem, and the size is just right between the iPhone 6 and 6+, but again, this phone feels too underpowered. Hopefully a few 6.0 updates will make it run smoother.
For what it's worth, we also have a Nexus 6 (last model) running Marshmallow and it doesn't have any of these issues.