I came across this helpful review on site build it. It basically explains in nutshell how it works. It gave me a good idea on what i can expect.
http://www.web-source.net/review9.htm
Also their "compare chart" gave me good overview on what they do.
http://compare.sitesell.com/
I will be digging for more information on them and will post here. I'm now seriously considering getting site build it
