I think there's a lot more with the Ultraseps, but it's been so long since I used the QS, that I cannot intelligently tell you the differences. I had a copy of QS that I used a few times (as a backup). Then I bought Ultraseps after watching the extensive video tutorial. I've since upgraded to V2 (no charge).
Doesn't Steve offer a staged upgrade to Ultraseps from QS? Have you asked?
I think you might be surprised with the extra features and results from Ultraseps as I think it was a complete rework of QS using totally different software techniques and methods.
I'll tell you what we can do. Send me an unsepped file you ran through QS Pro and I'll run it through Ultraseps and send it back and then you can decide if it makes enough of a difference to upgrade. The only thing you won't be able to see are the extra features available at run time, but there's probably a tutorial still available.