Taking AD2 out of the equation, I'm enjoying the control panel and PRV changes and I haven't really had a chance to do what hopefully mix recall is capable of.
 
I did migrate my preferences from X3, but I've had some funky stuff happen but it always does with a major upgrade. 
 
I'm pleased, but I'm not going to try to convince the X3 guys I know that they need this new version.  Like always it depends on what you do & what you already have.

resistance is futile

I'm convinced and ready to buy Platinum however, I'm in the middle of a couple client projects right now and don't want to risk ANYTHING taking up too much time at the moment. I also don't want to miss out on the special price, either. I'm assuming I can go ahead and purchase it and just let it sit there in my account until I have time to install/tweak it?? I mean, like it's not gonna self destruct or spoil or anything, eh?

If you buy it from the Cakewalk store the day you buy it is the activation date.  If you buy from third party like Sweetwater or JRRShop the activation date is when you input your redemption code into your Cakewalk account.
I got into the group buy from JRRShop for the discounted price of $126 and waiting until I build my new computer next month to redeem the software.

No self destruct!

I installed SP on my everyday PC. It worked like a charm. All older projects opened and worked like they did in X2 and X3. Worked with it a few days and went ahead and installed it on my off-line music PC. Opened some projects and started working and it's just as stable as X3e has been.

Love the new Control Bar. ReMatrix is really nice. I have many Reverb IR files and they sound good in this plug.

The Mix recall works as advertised. But I have not tried the Vocal Synch yet.

Karyn
I was recording a new song by my daughter yesterday.  She's a music student at collage.   Listening back to a harmony line that was clearly mis-timed she said she'd better go do it again as she starts heading to the mic.
 
Hold on,  says I,  I have a new toy....  as I open vocalsync on the harmony clip.  I select the main vocal as the guide and turn the knob...
 
She falls off her chair as the harmony snaps to main vocal.  She's very clumsy.

Karyn you have a wicked sense of humor! LOL

One of the things I really wanted was a substitute for Perfect Space, since cakewalk had discontinued this plug. Re Matrix solo seems like a great addition and it's available in Pro Channel as well. Perfect Space was a system hog on my 32 bit computers, but Re Matrix seems to fair better in this regard. I am in the process of transferring all my "wav" files across and this seems like a fairly painless process, although a better system of organising them would have been appreciated rather than just lumping them all in a "user" drop down. The full version of this plug is more than the cost of the full Platinum upgrade so I don't think I'll be upgrading anytime soon.
I like the addition to allow more freedom with the control bar modules, this makes it easier to work with on the laptop.
I haven't tried the midi updates yet but this seems to be a time saver and workflow addition that will help.
I tried 'Vocal Sync' on an eight part 'a Capella' song that I had recorded last year. I worked really well on some tracks but not so good on some others where the timing was too far off. There would have to be some editing done first to bring those tracks into line a little better before 'Vocal Sync' could work its magic.
That's about all the things I've had time to play with that seem to make any difference to my workflow as yet.

Even if the current version of Platinum doesn't have enough new stuff in it for you to justify the upgrade cost, I still recommend doing it. You'll also be getting the next year's worth of updates and additions for that cost. That being said, Platinum is awesome and runs great on my system. Gone is the "stutter" issue I had when playing back audio and jumping around on the timeline. The new UI (control bar, PRV, etc) look and feel awesome. Tons of reasons to upgrade! Do it and have fun :D

rodreb
I'm convinced and ready to buy Platinum however, I'm in the middle of a couple client projects right now and don't want to risk ANYTHING taking up too much time at the moment. I also don't want to miss out on the special price, either. I'm assuming I can go ahead and purchase it and just let it sit there in my account until I have time to install/tweak it?? I mean, like it's not gonna self destruct or spoil or anything, eh?

Buying an installing does not mean stop using a previous version.
 
And this new software will take a few months to fix.
 
And if it is installed you can test it with current projects for happiness. And explore some of the new bits.
 
And: DO NOT EVER UNINSTALL A PREVIOUS VERSION.
 
OK, back to work.

Well hopefully...
http://youtu.be/s28oq4W2PPk