SAM's rounter NightHawk X6 r7850 not working correctly.

Nighthawk X6 R7850      

I bought a Nighthawk at SAM's in February due to fact that my other router died.
Here my Problems:
Range, it's terrible. My older dual-band router had a better reception.
Connectivity, the new router has a bad delay, and sometimes it just quits transmitting. On all browsers, the pages will take very long to load, or we will get a blank page. I will get connection errors on Fire Sticks or smart devices. We have to reconnect at least once a week. Delete old connection, and then reconnect.

I have reset the router to factory defaults and updated firmware. I still have issues.
My guess I purchase a lemon.