I do. Just got it a few months ago as my first foray back into production. I love it, but I can't offer any comparison to previous versions as I only used to play with real-world gear, no virtual stuff. I'm sure there are others here who have owned earlier builds that can give some insight into the improvements (other than Thor).
I haven't messed with any sequencing or synth software in several years and I picked it right up. After watching a few vids on youtube and doing a little bit of reading, I was right back into the groove. With you already owning 2.5 I would think it would be a cakewalk to get it. If you're wondering whether it's worth it to upgrade or not, you would have to ask someone else, but I've read here and other places that Thor (new synth) is worth the price alone.