I don't think you get the point of tomato... you get live stat analysis on your router rather than having to use something like wallwatcher or samurize.
The config is actually harder than DD-WRT because it doesn't have built-in help and some fields are somewhat obtuse. Seriously after setting up iptables chains are you sure you want to spend more hours cracking your head trying to set up htb scripts for QoS?
If you want your usb support you can always try patching it in yourself. tomato uses busybox just like any other 3rd party firmware... then you can get people to worship your 1337ness.
I never had problems with L7 filtering on my lowly 200MHz processor... its just that the rule in &d00's QoS seems pretty useless if you use something like uTorrent.