I used the Ctrl-Stretch feature on selected MIDI notes in the PRV in SONAR Platinum today. IT IS REALLY USEFUL.
Also, I agree that for single track MIDI editing, the PRV does seem a lot more solid in Platinum than X3E. I like using it a lot.
Unfortunately, for multi-track drum MIDI editing with Drum Maps, I drop back to Sonar X3 Producer. I find the PRV almost unusable in that scenario.