Yes, you're correct, DD-WRT runs on modern consumer AP/router hardware. But the processing power* of that Asus (a quick google tells me 800MHz x 2 cores with 25

Yes, you're correct, DD-WRT runs on modern consumer AP/router hardware. But the processing power* of that Asus (a quick google tells me 800MHz x 2 cores with 256 MB RAM) pales in comparison to e.g. an Atom C2358 (1.7 GHz x 2 cores) with 4 GB RAM. You can't run DD-WRT on the latter, or at least not last I checked, which is the point I was trying to make (albeit poorly). And when it comes to running things like Snort, VPN, etc., you're going to want that extra memory and processing power. Granted, it's probably overkill for most people, but one might say the same about the Homebrew/Ubuntu solution described in the OP. The whole point of the OP was moving away from MIPS-based consumer AP/router hardware with small memory footprints. * And yes, the Asus has silicon dedicated to networking features, but so does the C2358.