I've used DesignBuilder for the last 10 years. Initially, it's capabilities were marginal, though helpful.
Since then, DB has steadily improved and is now my mainstay for almost every project. Their "hierarchical" data structure and input color-coding makes assigning inputs MUCH more straightforward and easier to check - this is a key element that makes model preparation much faster and error-free. In addition, they've added forward-thinking tools such as 2-axis optimization and continue to develop other capabilities.
Just as crucial, the DB support has been outstanding for the entire period, as has been their receptivity to suggestions!
DesignBuilder is an incredibly user friendly software which we have been using for LEED certification and energy certificates as long as many other applications related to building performance. I strongly recommend it for advanced and new energy modelers who care about building performance.
A must use software.