Many of you may know that Foliovision began as a client service agency and not a software company. Our first big service was migration from Typepad to WordPress. We were literally doing dozens of migrations a month at one point. Project management in bulk was essential to the premium client experience we wishes to offer.
We started with Basecamp but eventually outgrew it (there's a long post about our Basecamp to Teamwork migration) and moved to Teamwork (back then TeamworkPM). Teamwork Projects at the time had a much worse design than Basecamp (latest version looks pretty good and even allows CSS customisation) but lots more tools (recurring tasks was a big one for us) at the time. As happy as the upgrade in features made us at the time, there was still one key feature missing. Later we called this feature Observer Status.