Uh-oh, i see a mail in my inbox in the near future.
Also, it seems like the OP never clarified if he has AnyDVD or similar? I never really tested it on a still encrypted disc, its quite certainly possible that it will just crash.
I should try it.
To actually contribute anything remotely useful:
All H264 decoders have the same exact quality, unless there is a bug. CoreAVC may be faster (at least in software decoding mode), but it most certainly has no better quality, but also no worse quality.
PS:
It would actually be possible to play discs without AnyDVD, but you need two things: a copy of libaacs.dll, and a key file. Shipping the binary dll might already be a gray area, the key file most certainly crosses into black.
VLC offers the same support, and lets every user find these things on their own if they really want it.
(Also only works against AACS, not BD+ protections)