Controller wise, well that is a very personal thing and I'm really not 100% sure I want to go away from Hammer/Weighted action but I would not get rid of my PC88, just preserve what's left of it,
I know I would miss not having 88 keys ( 76 key controllers are out of fashion I guess).
To add to the chaos, NI is throwing a discount on Komplete / Std or Ultimate *crossgrade if you buy their controller. But I have heard good and bad on those as well. Seems the Arp and some other items don't always map correctly to DAW's in general ( not a slam on Cakewalk, but a slam on NI )
Speaking of Cakewalk, just because we are having this debate doesn't mean that I won't jump on board the new stuff. I'm just cautious AND cheap!! The fact that the "Bakers" are improving things and adding new features is totally positive. It shows that this is a platform that is in it for the long haul. So many "new" DAW's popping up here and there and then "poof" gone tomorrow. The Big 4 have stood the test of time. Thank you to the "Bakers" for trying new things. You can't have bugs in the code if you never touch the code. So keep up the good work.

As home hobby player, I have found nothing deal breaking in Platinum itself. They may be fixing and adding something important for other while not touching extremely buggy part (since years) I use. But in case you would like to have more AD2 packs, upgrade is a good way to get them.
 
Rapture Pro.... beta version at most. And while other have introduced Kontrol and Advanced, they think that Touch is the only way you want to select the sound of your synth. They have exposed many hundreds parameters, but I have not found the only one I need. May be Tascam is planning to produce MIDI keyboard with build in touch screen?

Andrew Rossa [Cakewalk]
We are going to do be doing updates every month. I am sure we call all agree that all software has room for improvements. Don't take the fact that we have done 4 updates as a negative. In fact, we'll be improving SONAR (even though it is very mature and stable) every month and making it better and better. That should be viewed as a positive instead of doing a few patches like most software companies do and moving to a new version.

I'm trying to figure out how this was a reply to anything in my post, but maybe it was just random. I am happy there have been 4 updates to what was really a fairly stable initial release, and I'm looking forward to the next one! I'm a pretty happy Platinum camper and totally down with the new model. I just speculated that it might not be the best use of the OP's money given his description of where he's at...

subtlearts

Andrew Rossa [Cakewalk]
We are going to do be doing updates every month. I am sure we call all agree that all software has room for improvements. Don't take the fact that we have done 4 updates as a negative. In fact, we'll be improving SONAR (even though it is very mature and stable) every month and making it better and better. That should be viewed as a positive instead of doing a few patches like most software companies do and moving to a new version.

I'm trying to figure out how this was a reply to anything in my post, but maybe it was just random. I am happy there have been 4 updates to what was really a fairly stable initial release, and I'm looking forward to the next one! I'm a pretty happy Platinum camper and totally down with the new model. I just speculated that it might not be the best use of the OP's money given his description of where he's at...

Ah, you are right. It was meant for Paulo but I think I clicked the wrong quote. I fixed it now. Sorry.

Andrew Rossa [Cakewalk]
 
We are going to do be doing updates every month. I am sure we call all agree that all software has room for improvements. Don't take the fact that we have done 4 updates as a negative. In fact, we'll be improving SONAR (even though it is very mature and stable) every month and making it better and better. That should be viewed as a positive instead of doing a few patches like most software companies do and moving to a new version.

At no point did I say that having 4 updates so far was a bad thing or negative thing, I simply stated that going by what I read here there still seem to be a few issues with it (some of which seem to have actually been caused by the regular updates). The OP asked for opinions from fellow CW/Sonar users on whether he should upgrade or not and I gave him mine based on my observations of the new version so far.
 
FWIW I think it might still  be a bit early for you yet to lambast the way "other" companies give you " a few patches and then move to a new version" . Last time I loooked (yesterday) the Undo function does not work properly in X3E which was a known issue, yet here we are with a new version and that very simple, but very annoying fix has now been completely forgotten because ................hey everyone, we have a new, new version now.....

Andrew Rossa [Cakewalk]
Ah, you are right. It was meant for Paulo but I think I clicked the wrong quote. I fixed it now. Sorry.

No problem from my side, I was just a bit confused by it. But then I'm often confused...

paulo
as I understand it you won't get that stuff anyway as you have to be a "member" at the time it's released

FWIW that was true only with the Brian Hardgroove bass loop library. It was created as a commercial product, but Brian switched to SONAR last year and really likes it, so he wanted to support the Membership Program by making his library free for one month to the "early adopters." All the other content (so far) you get later on. There may be other instances in the future, though, where content is pegged to a specific month but I don't know of anything like that planned at the moment.
 
A good way to find out what's in the releases is to check out the PDFs of new features. For example, they list the bug fixes, enhancements to Mix Recall, etc. as well as descriptions of the content.