The Cakewalk folks did a complete redesign of both the internals and the user interface of Sonar, beginning with X1, and is now a couple of releases past that with X3e being the current level.
They had multiple reasons for doing the redesign, partly because of functionality changes, and also due to a desire to make things much easier for folks to use.
Sonar 8.5.3 was a beloved release, and it has taken until the X3e release for the new design to really come into its own, with all kinds of praise for its work flow and for its stability.
X2 is still quite usable, it does have some bugs that weren't addressed until X3, and also some functionality and bundled software differences than what is in X3.
Nonetheless, if you take a bit to orient yourself with X2, and hopefully some point with an upgrade to X3, you too will come to find things have really changed for the better - even if it doesn't look like it yet to you.
8.5.3 was very very powerful, but it was a black arts kind of affair, with all the key combinations to get things to work in a quick fashion, and the X series sought to make getting things done a lot simpler for a wider base of existing and new users. In that, the X series has done remarkably well.
Some things are moved around a bit, but most things still work the same way, and there are all kinds of free videos and tutorials available for X2, as well as really well done 3rd party books that explain things in great detail.
In addition, there is a giant community of folks here in the forums that will go to great lengths to help you get through the learning curve of the redesign you see in X2.
Many many folks, myself included, felt quite confused, frustrated, and even angry, at the redesign that came beginning with X1, but just about all of those same folks came to find that once they got used to some new ways of getting things done, that they actually improved their work flow and finished projects in the new X series.
Sooooo, hang in there, look at the Cakewalk site and YouTube for all kinds of short videos on just about every kind of function there is in Sonar X2, and post questions to this forum for whatever else you want some quick help with, and folks here will do their best to help you out.
Bob Bone