Fingerprint sensor is better than Samsung imo. Yeah too felt the device will break into pieces if dropped due to its very slim design and many oneplus users faced it too. Due to less service centers it is very hard to repair. They even have policy if service center guy opens the device to check what's wrong inside the phone you have to pay Rs 300 for it. Nougat hasn't bought much changes over Marshmellow comparing to what i got in Samsung Galaxy S7. They also have lesser software update these days comparing to what OnePlus 3 got during its early days.
Overall i feel Moto Z Play is preferred buy as of now. OnePlus 3 is good in processing because of its RAM, dash charge does the job and instantly power up the device. Other than that nothing special. And yes, the accessories are over priced. After using them for some days i realized. Comparing to what quality Samsung gives at those costly prices.
Congratulations bro.