We were using CE for the last, almost two years now. The problem was that if there was a bug you would usually have to live with it for a few months before they fixed it. Requests took them six months to a year to implement if they ever did. Most of the time you would just get ignored. A lot of requests forum threads would get 20-30 posts long and just disappear or fade away. Not to mention the fact that the newest version, still in beta, is just now implementing some of the features that were requested well over a year ago, and that most other systems already have.
We used both MB and AWBS each for about two to three months. AWBS I don't really have to go into... it's simple the client front end is nice if you want to use their templates / layout and the back end/admin is a mess. MB is limited on the integration (ordering only) full of bugs, full of bugs, did I say full of bugs , and their support, and constant lies, and it is way over priced for what it's worth, and, and, and, and ......
There are two of us here that can script pretty well. It wasn't just the matter of time involved. It was the matter of how much we could save if we could just find a good system!!!!!! <- put some emphasis on that!!!
It has been a long search but WHMCS with the support of Matt is just that system.