Seems like I have to reboot several times a week ?

I have a Nighthawk MR 100 connected to the AT&T Lite system. It works well. But now and then it slows or stops. Then I have to reboot, once I do that, all is fine. 

Is this an issue in general with this model or my unit? Is this a "cache" issue? 

Since I have to use a router connected to AT&T, is there a better model that I should look at?