I echo the consensus about the drab color scheme, and the oft-repeated complaint about retaining prior settings when updating.
I just installed 9.5 yesterday, so I’ll use it awhile before I take the survey. A few early impressions.
Did the Pre/Post fader switch in the Send Rack get reversed? I thought at first the default setting had been reversed, then I realized that Sends I’d set to Post-Fader in existing projects had actually been switched to Pre-Fader. THEN I realized, no, this isn’t the case, only the COLORS had been reversed, apparently for the purpose of confusing me 
Seriously, what is the rationale for this?
One big selling point for me was customization of the metronome - this alone was worth the price of the upgrade from 9.0
So far, however, I’ve found the interface confusing - I was not able to make use of the enhanced features out of the box. I’ll have to watch some tutorials to learn how they work. A couple things that REALLY bug me are: “Control-Activate Metronome” no longer opens the Metronome Setup Window (hopefully I’ll figure out how to setup a key-command to do this, but it seems strange that this would have been removed from the default installation). Also, the procedure to select MIDI CLICK notes is really weird, ONLY selectible via a horizontal volume slider (used to be up/down arrows, mouse wheel, or directly type-in your selection). I’ll get used to it, but why, when trying to improve a feature, would you “break” the parts of it that already work well?
And (this is an old complaint, going back to version 7 I think?) Am I the only one who still can’t get used to the super-skinny slider bars (at the bottom and right of the project window). They are so thin I often have to try several times with my mouse to grab them. The Horizontal Zoom bar in the lower right corner is the worst. Most often I use the + and - buttons to zoom in or out incrementally, but more than half the time I miss and get a maximum/minimum zoom instead (neither of which I have found a use for).
So, that’s my gripe session for today. I assume I’ll figure it all out and eventually be happy I upgraded, but it’s annoying that upgrading always has to be such a time-consuming hassle.