Excavator's API has a pretty interesting minimalist design philosophy, which is refreshingly different from sgminer etc.
I would imagine its merits would become clearer as we add more features and algorithms and develop helper applications that take advantage of it.
As for raw performance, I will do everything I can to make it a top-notch OpenCL miner.
Now that I have more time and resources, I can try things that were previously impossible for me, and I am really excited about that.