How would you say the stability of this release compares to the last version?

I understand it's very new software, but the last version I played with (1-2 weeks ago) was incredibly buggy. Not just in terms of core functionality (hanging packages etc - some of which I see you have addressed https://github.com/kitematic/kitematic/milestones/v0.4.0) but just in terms of the general UI, buttons randomly disappearing/appearing.

I was/am really looking forward to using this but the bugginess did not give me a lot of confidence that the behind the scenes logic was behaving as expected.