When I first started building sites using WordPress, I downloaded a few different themes and took pieces from each to build the sites my clients wanted. Each theme had its own peculiar way of implementing things and, of course, with each new theme used I spent precious time learning that particular theme developer implemented their features.
In the summer of 2012, I learned about StudioPress. I read their blog and searched for sites that were using their themes. I was impressed with the diversity of the sites built with the StudioPress Framework.
I purchased the framework within the next few months and have been very happy. The support forum is moderated very well providing answers to questions about particular themes and advise on how to implement your own features. I found the third party developer community is quite active and, therefore, I am able to find plugins coded specifically for the StudioPress Framework to bring advanced functionality to my sites.