I agree that video quality is more important than bonus features.
I haven’t looked at all the discs yet, but I think the solution should depends on how much space the bonus material takes up. If it could be 3x feature BD25s and 1x bonus disc, that sounds good to me. If it would be 3x bonus discs, I think it would be a much better decision to use 3x BD50s than have a 6-disc set.
Yeah if I were you I would consider a bonus disc. The film itself takes up so much space and even with just the film, nothing else, at BD25, you’re already most likely sacrificing some quality, so you’ll want as much space as possible.
Were you able to get the dts audio working with encore? I’m curious how you got around that since you seem to be foreign to the multiAVCHD process. This has been the biggest hurdle with my BD project.