If you need stability, go with a high end consumer router and load OpenWRT/DDWRT on it. OpenWRT and friends are very stable, but don't often take advantage of advanced features like automatic channel selection, traffic prioritization, or beamforming.
If you absolutely need features, go with a ubiquiti AP. My only issue with them is their hardware leaves a lot to be desired, and is rarely powerful enough to cover a full home, this isn't necessarily ubiquiti's fault though.
Business class APs expect you to set up multiple APs in the office, so their hardware is typically a lot less powerful than what you'd see in a consumer wireless router. A ubiquiti AP will gladly cover your 1 bedroom apartment, but don't expect it to cover your 3 bedroom home
DD-WRT has been pretty solid for that, even in non-ideal network setups (currently have it connected to the ISP router as a 2.4GHz client, then acting as a 5GHZ AP for my other devices).
They're very popular in Europe but oddly never seem to have had the same impact in North America, although you can find them if you look around a bit.
They did do a linux based variant at one point but switched back to their custom rolled OS a couple of years back. Not sure of the story there or if it's possible to do a custom firmware. There was something on google code at one point.
As an aside, if you're after a nice, fast, low power solution, you can also look into the Netgate pfsense hardware, eg, http://store.netgate.com/ADI/RCC-VE-2440.aspx.