Bought one today, ended up going the HD240.... only because of the amount of air it can generate and was more suitable to what I want to do with it, and it was the biggest one I could run off a 10amp power supply.
I almost actually bought the HD300 but I didn't feel like getting a 15amp socket installed etc. the HD200 was a toss up also, but I wanted the bigger flow unit and I don't plan on doing any heavy duty work with it so I'm sure the direct drive HD240 will be reliable. Its not as noisy as I expected either.