Need Router Help/Suggestions!

[PartyWaffle]

So here's the skinny: I have had a Trendnet TEW-812DRU for a few months now. I purchased this router specifically for speed and reliability. I have 9 people in the house and each on with a couple of devices so there are no shortage of connections being made to the thing since everyone has at least a phone and computer. But anyways, like I said, I wanted speed as well and that's where I've been having problems. Some days this thing works great and other days I have to completely reboot it. I know 2.4ghz isn't very fast, but I have 100mbps down and only get about 40mbps on wifi. On 5ghz it's a little better(70mbps) but it's still cutting some speed. Keep in mind that I am less than 100 feet from it but still on the same floor with really just a door in blocking signal. Lately I've been having to reboot the thing more and more because my connection will just slow to a crawl. I have turned off most of the odd features that are supposed to prioritize the connection and all that jazz. I've contacted Trendnet and am supposed to be sent a replacement unit, but now I'm wondering if the same thing will eventually happen. Is router degradation common? And if that is a thing, what are some fast, reliable routers that you guys can recommend for my nearly 3000SF home? Bonus points for anyone that is in a similar situation with a rather large amount of devices as well.

 

Forgot to mention that there are 2 devices hardwired to the router as well.

 

I'm considering this: http://www.amazon.com/TP-LINK-Archer-C7-Wireless-1300Mbps/dp/B00BUSDVBQ/ref=pd_cp_147_1?ie=UTF8&refRID=1D23BMT7FARMYTSZYE37