I had Reaper for a while but found it, well, kind of geeky and FAR too full of parameters for this, parameters for that - a huge Christmas tree of stuck-on baubles; you might as while write the code yourself.
I've had Studio One for long time and got well into it, but parked it a while back because it really doesn't cater for MIDI so well as Sonar. In fact, when it was first written the designers seemed to be of the opinion MIDI was a dying thing so hardly bothered with it all - there's no facility like Sonar's Instrument Definitions for using external MIDI hardware, for example. It's screens are cramped compared with Sonar's and text is small.
My guess is that Sonar will continue, albeit with a small team behind it operating with very low overheads, kind of boutique-like.