Gradient, some speed tests were done, but they didn't generally indicate such a dramatic performance loss. I will agree that not testing on the currently available benchmark scene by Karsten was an oversight and I will be sure to include it in future tests of alpha builds for comparison.
That being said please do keep in mind that this is a pre-release Technology Preview. Our current focus is on feature implementation and bug fixing. The initial Technology Preview release had many well-known problems, some of them fairly serious (frequent crashes, etc.) so fixing those issues was of greatest importance for us on this update release. Speed improvements are always desirable and will be implemented as time allows, but hopefully you'll agree that actually being able to work in the application without worrying about crashes is a bit more important than rendering as fast as possible.
You can still look forward to very significant optimization in the future. Perhaps it will not be enough for you, but only time will tell. In the meantime if the ups and downs of these update releases - the 2 steps forward and sometimes 1 step back - bothers you then I would simply suggest taking a break from TG for a while and waiting until the final release. You have to accept a certain amount of frustration and "wasted" time in dealing with any pre-release and its inevitable shortcomings. If you're not prepared to do that, there is little use in following the every development of the program and being upset when it doesn't go in the direction you want it to.
I do hope you'll enjoy and be able to comfortably use the final release but I don't think the Technology Release period will be of use to you given what you've said so far. We certainly didn't intend it to be used by everyone; if we thought it was ready for that we would have released it in final, or at least as a beta!
- Oshyan