I don't see much there, that can't be accomplished with P5 (and a couple of plugs) now.
There are some similarities though. I have Sonar 8.5 and love it. But what Cake never figured out, was that the pure simplistic approach with P5 and the lack of all the luster is what made it so special. I use it almost every day. It is my scratch pad and my tune tester. When I want to just sit down and experiment with new ideas, I start P5. If after I find that I have come onto something that I really want to pursue I'll port my project audio and midi file over to Sonar and start a more in depth approach.
I love Cake products, but I think they really missed the boat of letting P5 slip into obscurity. Maybe they will find a way to resurrect it.
I feel they never really put an effort into marketing it, because if they got it into more peoples hands, it would have out sold almost every other product they make.