Tripecac
I'm a long-time Sonar user (since the ProAudio days).  I use it primarily for MIDI and soft synths.
 
My favorite version was 8.5.3.  X1 and X2 and X3 added "stuff" but didn't improve my productivity or enjoyment of using the program. 
 
Does the new version of Sonar significantly improve the UI for those of us who are mostly dealing with soft synths?  Does it increase the customizability?  Does it give us back some of the control that X1/2/3 took away from us?  Does it improve your overall workflow/efficiency?
 
Or does it just add more "stuff"?

Man I read your post and it was like I typed it myself.  I apologize I barely read the forums anymore maybe once a month and I was too lazy to even read this whole thread.  I just want to reiterate your words "8.5.3 was the best version for me."  I'm using X3 now and it's fine but it hasn't added anything.  Except for a bunch of stuff I don't use.  Again I apologize, guess I can't throw stones towards the newest version of SONAR since I haven't upgraded but I've completely lost interest.  It's not getting the colors back to the way they were in 8.5.3?  Aside from a bunch of workarounds I don't want.   I definitely don't care about the cost, and I definitely don't want the any of the 'stuff'.  I want a really stable program, actually with no 'stuff', and I think I'm in the minority.  But anyway nice to read your post.

I for one am glad for this post. I've never been able to convince myself that upgrading from 853 will be worth it. I would like to, but for me, the workflow in 853 is perfect. I compose for orchestra, and I need to see that long track view list of instruments. the skylight interface appears to have done away with that. I can see that for most, it's probably an improvement. But there are a few of us who prefer the "old ways."

I definitely don't want the any of the 'stuff'.  I want a really stable program, actually with no 'stuff', and I think I'm in the minority.
 
I'm with you.   Hell with the craplets they keep adding: just want a fast, effective, piece of software.
 

Travis - I went to your website and listened to some of your music, and based on what I heard I would tell you that you can stick to Sonar 8.5. You're right: you don't need the extra content that was added in the "X" series or in the new version released this year. Most of the users on this forum have found X3e to be super stable, as is the 2015 release, and while that stability is probably all you need to do the work you're doing, those versions do have a bunch of "stuff," as well as a UI you don't like, so why not go back to Sonar 8.5.3 and make yourself happy? Or even switch to something like Reaper, which is very affordable and doesn't come with much "stuff" at all?
 
On a personal note, I was the owner of a 2-inch tape-based 16-track studio in Hollywood back in the day. I also visited many of the studios in LA, and I knew a lot of other owners, and I can tell you that among the pros there was nobody saying they did not want to try out the next piece of technology, no matter what it was. And the creative ones often would find a way that nobody else had thought of to put that new technology to use in ways that changed the business. The only reason any of us did not "upgrade" every month was money. The big guys who had the bucks were constantly acquiring new gear and using it to make great sounds. So now that we have a hundred times more power than even the fanciest studios in the 70s, and for only a few hundred dollars, I think you and I are really lucky to be living and working in this digital era. I look forward to learning the new stuff and using it to make music. I keep an open mind about the changes that Cakewalk puts into the program periodically, and who knows? I may do something really great with it some day.

I've been using Cakewalk since the Twelve-Tone PC; Midi only days; not too happy with the subscription fee thing; will go the one time fee I suppose; would really like to see some better editing capability in the piano roll department along the lines of Cubase.  For some reason I don't mind paying a sub fee for Netflix, but I much prefer an upgrade every several years and one time fee versus the sub model for work software.   Not very happy, but I'll try the new version.

Stay with whatever version makes you happy. No one makes you upgrade. It's voluntary.

But there's obviously lots of folks who have upgraded and are making good music with the latest version and prefer it to 8.5.3

It took me ages to like the Skylight interface, but once I stopped going back and forth between the X series and 8.53 I found the benefits. I also relaised that the Sonar that was 8.5 was not going to be enhanced any further and if I wanted new features there was only one way.

Every now and again I open 8.53 for an old project and I gotta say it's an ugly crowded mess where things are just so difficult to find.

It seems that much of the OP is geared toward UI issues and work flow features. The UI didn't revert, and most likely never will, but some enhancements have been added. As far as features, the best way to check things out is to read the release notes and the forums (as they are added).
 
As you own X3, that is really the best "test bed" for what is an what you would like to see. X3e made the most "quantum leap" IMO as far as stability and features (Speed Comping, ARA, VST3 support, return of some color options, etc). If X3e is still bothersome to you, it is pretty much all still there.
 
[And now for the candid downside...] Being a hobbyist as well, I find most of the "stuff" less than impressive which is only exacerbated by how the Command Center distributes this "stuff." I have actually spent more time cleaning up/managing installations than I have doing anything music-related with Platinum to date, so new features have been far overshadowed for me (I cannot even rattle off what they are because I have used so few). It is almost like if I want to make music, I turn to X3; if I want to do computer maintenance, I use Platinum. The "stuff-fest" concept is the Achilles heel for me to use Platinum for the purpose of making music.

MusicforMovies
I've been using Cakewalk since the Twelve-Tone PC; Midi only days; not too happy with the subscription fee thing; will go the one time fee I suppose; would really like to see some better editing capability in the piano roll department along the lines of Cubase.  For some reason I don't mind paying a sub fee for Netflix, but I much prefer an upgrade every several years and one time fee versus the sub model for work software.   Not very happy, but I'll try the new version.

The recurring fee *only* applies if you choose to go month to month. As has been explained innumerable times if you pay the annual price there is zero difference from buying it outright and you permanently own the software so you can choose to update after many years just as before.  Here is a link to an excellent review on SONAR that features an interview with Jimmy Landry who answers several questions about membership.
SONAR has tons of editing enhancements in the piano roll so its not clear what you find missing. There is also a brand new pattern tool.
 
Regarding people upgrading from the pre X1 days, yes the UI is different so for some folks it might be a bit of a learning curve. However there is no question that in terms of stability and depth SONAR is light years ahead of 8.5. There must be thousands of issues present in 8.5 that have since been resolved! The UI in 8.5 is not adaptive and it had a great deal of redundancy and clutter making it very difficult for new users to learn quickly. 

mudgel
Stay with whatever version makes you happy. No one makes you upgrade. It's voluntary.

such a shame we can't get the fixes without the rest of it eh?

Noel Borthwick [Cakewalk] There must be thousands of issues present in 8.5 that have since been resolved!

if only they were acknowledged and fixed at the time, eh?

I'm sure we'll figure out how to do that once software engineers learn how to predict the future.