I've been through many horrible, consumer grade garbage wifi routers over the years (10+ probably of them) running openwrt, tomato, dd-wrt, stock firmwares and most recently a ubiquiti. Eventually they all begin to display some sort of instability or poor performance just due to the terrible hardware they ship with (the days of a cheapo wrt54g running dd-wrt with perfect stability are over it seems).
The only consumer grade wireless AP i've found that stands the test of time is the apple airport extreme. I have 3 of them spanning 3 generations of the product and they've been rock stable for years. I can't speak for how well they work for routing, i use them strictly as an AP. From there i run in alix board with pfsense to handle all of my routing needs and 2x 24 port dell managed switches for all of the devices throughout the house. This is the cheapest, fastest and most reliable system i have been able to come up with and i hugely regret throwing away so much money on d-link, netgear, linksys, buffalo, ubiquiti, and asus garbage. Long story short, save yourself the hassle and pay a little more up front, it's not worth the gamble.