I’ve upgraded, and as others have stated C5 is still there if I want it.
I work a lot with acoustic stringed instruments and some the new features are a big step forward for me - especially the time stretch algos, the comping, and general multi-channel editing.
There are lots of small but useful enhancements such as automation nodes that expand with zoom making them much easier to use.
Graphically there is a big improvement although it must be said that the slightly unfamiliar surroundings are a little disorientating, but one gets past that pretty quickly
The Halion Sonic SE is a whole lot more useful as a box to run HSO out of, which I use a lot. The previous HSO interface was a joke! Note expression is looking good although so far I’m only tinkering with it.
I’d also considered the issue that C6 might not perform well on my system so looked on early adoption as a way to test drive that and identify any issues. Actually, I needn’t have worried.
Yes there are few bugs but TBH they don’t really interfere with my workflow. the most annoying thing (for me) so far is one of the pan handles can be a bit sticky. Not exactly a huge deal. I can live with these sort of things until an update arrives. It might be different if the thing didn’t work or kept crashing, but it doesn’t. For me.