In that case, I think you guys will probably find it beneficial. The only thing our CEO would like is an additional report that uses a different algorithm for calculating potential revenue. He disagrees with the way the default calculation.
I checked out the source and it looks pretty clean. I told him with a little bit of time, I could create the new report for him, but we're busy doing other stuff, so the CRM system gets no attention. We're overdue for updating it too, just haven't had the free time.
Another one to look at is vtiger but I haven't done much other than look at screenshots, they all look pretty much the same to me.
I'd say SugarCRM is the main choice of those that don't use Salesforce. Big community.