I was tracking a band (a band I've recorded many times since X1) this past week using Sonar and arming 17 tracks per drum take. Other than not being able to record multiple takes per project (Comping mode) due to Audio Dropouts, Sonar
never crashed! Before in X1/X2, it crashed every session, several times! (Yeah, I'm still hurting from the X2 issues -- I won't ever forget how bad X2 was for us). But Platinum is working just fine!!
It did crash when I opened a few Waves plug-ins for the first time since Platinum was installed, but otherwise, it's been solid.
A few minor gripes, still:
1) Clicking Apply and Close for Preferences hoses up the system for a good few seconds, many times when adjusting I/O buffers.
2) Still some wonky-ness in Take Lane expansion when Auto Zoom is enabled. Sometimes the wrong Folder expands.
3) At times, editing Gain envelopes (automation) still gives me issues when I'm not able to add, edit, or move automation points. This is an issue I've had since X2, and reported it a few times. Spend some time with envelopes, and it'll show it's face.
4) Faders are still too small, especially for 'touch'.
5) Sonar seems to introduce static when pre-mastering with loudness, depending on the plug-in. It still can't handle this task inline, especially when mixing. In other words, if I'm intending on creating a very loud master, I can't use Sonar to accomplish that to a professional degree. I don't use Sonar for Mastering, since it lacks the metering and other Mastering tools I require, but for a quick "check" on dynamic pressure in a loud mix, it works pretty well.