Come to think of it - check out commentkahuna as well now. It's similar and free. Don't get as many results from commentkahuna as I do with comment hut - but free is free
I've experienced the same thing with MU being a hog - but with this type of method your not doing huge volumes of traffic and a large part of it is being converted on the "free hubs" like squidoo. The seo traffic down the road coming to your mu sites is just for you - - since your not letting others post there it's just your stuff. When you have thousands of people posting to MU it does get awful heavy fast. But....
Resource hog is fine if the person is looking for exactly what your pushing and your only dealing with your very targeted ads and offers.
I find that doing this I don't get zillions of visitors, just handfuls of people looking for just what I've got on the page. Conversion is great, and follow through (with ordering) is great. It's great for upping your rankings with affiliate programs as well so you can get them to up your payment scale as well.