Not to belabor the issue or be argumentative but from what I've seen most of the new stuff has been separate downloads (aside from the initial release with the Control Bar, FX Racks, PRV stuff). Drum Replacer was separate as have been other items. The new aux track stuff really couldn't be separate because they are baked in.
If you look through the releases really most of the core downloads really were bug fixes and enhancements. The flash and dash were kind of side dish/separate downloads.
Really though I think if we were getting the types of bugs that X1, X2 and even X3 introduced over the year then it would be a problem but really if we take the most up to date/patched version of X3(e) as a metric for bugginess/stability it was actually more fudged up and problematic than pretty much all the Sonar 2015 releases.
And you were STUCK with those bugs once Cake decided to stop working on a version (which was what led to me howling like a baboon once they bailed on X2).
Basically if even a couple of the Sonar 2015 releases ended up less useable than X3e was then I could see it being an issue but that has not been the case so far. I was concerned about that as well and the new delivery method required a LOT of trust on our end (a commodity I in short supply of) but so far the Bakers have held up tot heir end of the bargain.
Some users, with specific setups, have gotten temporarily burned on a release or two but they were outliers and had the rollback option and/or usually got a fix rather promptly.
It comes down to are we experiencing MORE or LESS showstopping bugs than we were before? I'd say, from personaly experience, FAR less and at least now when those things do come up there is a good chance it'll get sorted out whereas before you were simply stuck for a year until the next release which may or may not correct the issue.
I don't think that's a naive or overly forgiving assessment of the situation. If it sucked I would say so.
Anyway... if anyone is having problems just report them so the Bakers at least have an opportunity to correct the issue. Not just for you but for everyone else having the same problems.
Cheers.