Clicking stuff in the GUI is fun, but hard to maintain. Who knows what security problems you're exposing. (CGI scripts written in C and sh? I think the entire Internet crashed in the early 90s because of that...)
The problem I've had with cheap routers (Linux or otherwise) is that their state table fills up and then it stops accepting connections. I was at a conference with flaky Wi-Fi once, and kept losing my ssh connections. Eventually, after only about 10 dropped connections and IP changes, the router's state table filled up and the thing was dead to the world. No ping, no web interface, no routing, no ssh. Dead.
And then when the states expired the next day, it was back again.
I'll take http://www.polarcloud.com/img/ssbn100.png running on $50 hardware any day. And yes, it does QoS (http://www.polarcloud.com/img/ssqosg108.png).