My 1st DAW was Cake's Sonar.
2nd was Presonus Studio One. I still have both.
I've just recently bought Cubase 7.0.5 as my 3rd.
All full & updated versions.
Since I'm brand new to Cubase, I don't have any knowledge of past versions nor reasons to complain about this one.
So far I like it much more than the other 2, and decided to make it my preferred DAW, putting the other 2 on the shelf.
If you're only [or mostly] doing Audio, many prefer Presonus Studio One.
And while I will quickly agree that it is hard to navigate at first & for the first while, they do post numerous videos on their site, accessible from their home page - no account, registration or sign up needed to view.
There are also so many users that like that DAW, that they have posted their own videos & tutorials.
One guy even has his own site dedicated to it, and will even do a video for anyone on the forums just for the asking.
Most agree that "ONCE YOU KNOW YOUR WAY AROUND Studio One", it is very fast for work flow. But again, that can take a while - even quite a while for some.
The only the reason I have shelved it, is because I do mostly MIDI more than anything else, and Presonus have admitted that they don't really care about MIDI all that much, and hence have left out some important features that I need.
In addition I found it more anti-intuitive for MIDI than easy and quick to use.
So for me, it's more of a disappointment than anything else. I haven't done any Audio with it, but it's known to have a very good sound engine.
Further more, they continually gloss over or just ignore any MIDI improvements all together in their updates and new versions - or add very minor MIDI things to it.
Cubase offers me more - much more MIDI tools & options than the others, and like I said - so far so good.
From what I can tell, Cubase is way ahead of Sonar and others, so myself, I'm going ahead full force with it.