Hi, we're using the refinery for our pipeline. One problem is that due to the way its designed it's not very straightforward to copy/paste the processing code, which wouldn't have mattered if it weren't for the fact that refinery.jar is terribly slow. Now, it's probably partly because of my computer, but there's about 30~ second delay on every operation when you're in the GUI. Also, the whole program is a chore to deploy in a production pipeline because you can't simply just copy it around, you need to install the correct version of some java runtime, which I think is a totaly uncessary requirement.
Frankly I think the whole gui is dumb and it should just be a simple command line app. Unfortunately we don't have anyone working on this full time now so it's unlikely there'll be any huge changes from us in SCEA.
When I was working with Refinery I never saw the big delays on every action that you're seeing. I'm really not sure what it could be. The best thing for you to do is probably to copy out the code you need and wrap it in your own lib.