Why I get so frustrated

Software evolves, interfaces change. If software companies adopted a policy of never changing interfaces then we'd still be clumping around in Windows 3.1. Every now and then there's going to be a major overhaul of the software you use. It doesn't happen often, but when it does it's going to piss some people off. There is simply no way around that. 
 
You have to realize that Cakewalk has many different users to cater for. Longtime users are always going to insist that their prolonged loyalty to the product should be Cake's first and foremost consideration and that making changes they don't like is a "kick in the face." The reality is that Cakewalk would not be able to financially justify maintaining the product if "longtime users" were their only customer. They must continually attract new users. Not just refugees from other DAW's but also complete newbies who have never used one before. Without these customers you would not have Sonar. To attract new customers and compete with other DAW's you have to rethink, redesign, improve, overhaul, innovate.
 
I've been through all the changes to Windows, Microsoft Office, Quickbooks, Adobe products etc. Each time it provokes a litany of angry complaints. I don't like the way this works now, I can't find this feature, I miss this shortcut. Sometimes you just have to take a day to relearn a new design. But people don't bother doing that, they figure they're confident enough to stumble around in the dark and work it out themselves. In the process they miss new shortcuts and new features which have been designed to make things even easier than they were. 
 
Be honest - since the introduction of the Skylight interface, have you ever sat down and watched an up to date video course? Why not sit through the whole Groove3 course? You might well have more than one "aha" moment. 

Well the flip side is that you also have long time users just like yourself who are bowled over with the latest versions of Sonar and are amazed at how fast and stable it is now, and how useful the new features are. Now if Cakewalk were to say "OK we're going to scrap Skylight and revert back to the pre-X1 interface" then that would hardly be sensitive to long time users who think that Sonar is a much better DAW these days would it? 
 
I didn't mind the changes to Microsoft Office. There's always going to be a period of discombobulation, it's like changing cars. 
 
Another way to look at it is this. Learning new ways of doing things is very good for the brain. You're not only creating new neural pathways but you're also staving off dementia. I once read that something as simple as stirring your coffee with your other hand is "novel" enough to the brain to stimulate positive neural effects. 

I've become somewhat allergic to changes in software as well, due to the fact that I have so little time for my hobbies, and I don't want to spend it re-learning things. One point in changing things is that the old customers eventually pass away. The product has to be kept in a form that attracts new, young customers.
Another thing is, that the ever developing hardware makes more things possible, and fitting the new features in the workflow may require structural changes.

I work for a company that designs a software product (database) to professional end users, and my job is not to write it, but to teach how to use it. And changes are a mixed bag. usually they are a response to user requests and needs, sometimes it's because of changes in the environment and technology, and the competition that is more fierce than ever.  The cardinal rule, however, is that if you "fix" or change something, add a feature, try not to "break" something else in the program, or take something away so that it is more difficult or impossible to do. Especially for long-time users like myself and the OP.  But the user is free to move on if at some point another product becomes more appealing, and as much as a pain as this is (I'm avoiding it myself) it can be done. 
One more thing--the people who write the software aren't always the users of it--although in Sonar, probably they are. But there always needs to be attention to the user experience, not just "features."  That's a fine line. For the most part Cakewalk does this fairly well, but not perfectly, as you know.

MGC59
I must admit that Sonar 8.5 was my most productive phase especially for Midi editing. As xxrich stated: things that used to take one click now take several (Midi Plugins for example...5 steps to open!)

 
First of all, this is definitely a valid topic, and Sharke's response is spot on.
 
Anyway re MIDI plug-ins, if the browser is open, click on the PlugIns tab, click on MIDI FX, then just drag the FX into the FX rack. Much of SONAR has added a drag-and-drop capability that wasn't there before, which can be helpful. 
 
Generally, I find that SONAR does things for a reason, although any reasons may not be obvious because I don't think Cakewalk has provided enough information on optimizing workflow. To me, learning new features is an investment...I spend X amount of time learning new protocols, but these save me 10X time overall. I think what we need more than a feature or interface freeze is better, shorter instructional materials on how to get the most out of SONAR's changes.

Come on John, act like a grown up. There are more polite ways to get your point across. Be the bigger man here.

Glancing through this thread, I think users who don't like change and/or have trouble with inadvertent keystrokes will want to do some or all of the following:
 
1a. Re-bind F7-F10 (and their Ctrl-modified counterparts) to their pre-X1 functions.
1b. Same as above for any other bindings that don't work as expected.
2. Bind 0-9 keys to functions other than calling up their respective screensets or to "Do Nothing".
3a. Bind any other keys for functions you don't use to the "Do Nothing" function.
3b. Give thanks the Bakers for having already effectively done this for the 'O' key.
4. Take regular snapshots of your current mix so you can easily restore inadvertent changes to mute/solo states etc.
5. Smack yourself in the forehead and say "D'oh!" every time you try to type characters into a field without putting it in edit mode first.
6a. Become a dog person; a dog might lie down on your sustain pedal or step on a stompbox once in a while, but is not likely to walk across your keyboard.
6b. Take said dog for a walk whenever you feel frustrated by SONAR (or anything else computer-related). You'll both feel better.

MGC59
My cat walked across my keyboard in the middle of a mixing session. So many things went sideways that for a few minutes I wasn't even sure I was in Sonar! A magic button returning things to a previous state would have helped immensely! Not wanting to lose my work I had to spend a considerable amount of time researching and restoring things back to the way they were.
 
I am not a key stroke guy...habitually I like to click on things. I have been around since the Sonar 3 days.
 
I totally feel xxrich's pain.
 
There are a so many added features and extras that make me want to keep upgrading (other reasons being a changing hardware necessity)
 
I must admit that Sonar 8.5 was my most productive phase especially for Midi editing. As xxrich stated: things that used to take one click now take several (Midi Plugins for example...5 steps to open!)
 
The Sonar X and Platinum phase has been trying for me, to say the least. At the moment I am back to Ipswich because of constant crashes in Kingston. Many sessions end after a crash or a feature not responding or performing like they should.
 
I understand that plugins can cause these issues, but the number of these little issues has increased and my productivity and enjoyment levels have dropped.
 
I too long for the old day.....

CTRL-Z

I would like to think you are aware of the undo function? You can even see in the menu what you're undoing. If it's not undoable then it's likely related to the screen layout (I've hit screenshot shortcuts accidentally before and it's like whoa...). These things are trivial and can be fixed easily. Bottom line is you're not going to lose any work from the cat walking across the keys unless it hits quit and then "no" when asked to save...