OpenWRT is stable on many cheap platforms. It does so many things. The power provided by modern embedded device can sometimes give commercial hardware a run for its money, especially in the SoHo environment.
This talk discusses uses a moderately prices home router to provide most of the features you might want in a network: Enterprise WiFi, VPN (outbound AND inbound), network segmentation, redundancy, multi-wan, dynamic routing. Do a lot with a little.