I went with the crossgrade on Steinbergs own shop. They verified that it was ok to crossgrade within an hour (on a Sunday!).
I felt it was time to move on, deciding where to go was harder. The natural choice would have been Presonus Studio one V3, I had it since before and actually like a lot of things about it but I don't seem to be able to get really fluent with it for some weird reason. Reaper is impressive, and there are some brilliant solutions in there, but I would get confused by it all the time. Mixcraft was interesting and probably would be easiest to change to, but there's a couple of (just about) dealbreakers for me. So boldly/stupidly making the choice based on youtube and info on the web I got Cubase. I realise it's behind Sonar in some features (and better at some stuff) but the ara/melodyne-issue doesn't bother me that much, even though I have melodyne studio. If need be I can work melodyne as standalone, as a VST, rewire or even in Studio one, and if they add a couple of features to the Cubase solution I might actually never need melodyne.
Really sad day for me. I've used Cakewalk since dos version 2 (have the box still). But it really feels like whatever will happen with Cakewalk and Sonar in the future I would anyway want to change my main DAW, so might as well do it now when this crossgrade is offered - and I will try to change my feelings towards anticipation to give Cubase a fair chance. Last time I tried it was over ten years ago...