Nice. I like that the text style buttons work in the code view.
I did have a problem, but it probably isn't actually Sigil's. I usually start Sigil from calibre with the Open With pliugin. When I did this, it put up a MS Visual C++ Runtime Library error with Sigil.exe. The error was:
AN application has made an attempt to load the C runtime library incorrectly.
Please contact the application's support team for more information.
When I press the OK button, it Sigil starts OK.
This is on Windows 7 with the latest calibre 0.8.69 and whatever is the latest version of Open With.