I just moved from Iphone6+ to OnePlus 3T. My first time on Android.
I would highly recommend this to anyone, as someone who uses apple products for everything I was worried about the move however the switch was actually refreshing! As for the phone you can't really ask for more, £400 phone with higher specs than flagship phones.
If you're looking for the best spec then it's between OnePlus 3T and Google Pixel, for me OnePlus 3T wins hands down, only advantage I can see for the Pixel is having stock android.