I was literally just reading an old forum thread from a few years ago on Adobe’s site about this exact issue. I’ve was using DVDstudio for a long time but switched over to Encore last year when clients started asking for Blu-rays. Unfortunately Encore doesn’t support scripting, which I sometimes need, and it’s still buggy, with no support anymore.
In the thread someone suggested Sony’s midlevel authoring program DoStudio. Unfortunately I just looked and Sony dropped support and sales on March 1. So I’m not sure what our options are anymore between the simple consumer level authoring programs, and the ridiculously expensive Sony Bluprint (from what I hear, price isn’t published).
I do see that Sony is still distributing Vegas DVD Architect, though it seems they sold it to a subsidiary. In any case, I don’t know much about it. Hopefully someone else can chime in.