OK, so I guess I talked myself out yesterday, as I noticed the free trial icon on the UA website. I had to get Reaper to work with the plugin, so now I had 2 free trials running simultaneously.
Here's the good and the ugly thing about this piano.
The good: it sounds just like one of the pianos at my university! It's even slightly detuned, but not too uncomfortable like the Walker 1955 Concert D. The over all timbre sounds like the Steinway B when my professor has studio class with us. The resonances sound good to me, and the sustain pedal responds well to the instrument. There's also some half pedaling possibility with this plugin.
The ugly: no una corda samples. Sure, CC67 does trigger a pedal noise, plus some EQ stuff going on that I can't describe (what's worse, there seems to be a slight shift in the sound stage even), but it's definitely not una corda. If you're wanting to do classical piano and if there's something going on where the una corda effect is desired, it'll not give it to you. It's another piano that I'll not be buying after this trial!
Over all, I rather enjoyed playing this plugin, and it responds very well to my touch. But the lack of una corda samples is not making Ravel Grand a keeper in my list of piano VST's.