Finally picked up a 3D BD (G Force) to try on my new Sony HX929 with the 104 glasses - much better than I expected, pretty cool actually.
I got mine from Amazon and they are the Large size. Comfortable enough (I have a very large head) and the tilting problem is far less than I expected from the comments - you have to tilt your head like 45 degrees to lose the 3D.
Be careful on ordering these from Projector People - there are some questions as to color and size, and the responses from PP indicate they are unaware of the size and that the ones they sell are black, which is not the L versions from what I read. Mine are clearly marked LARGE on the packaging and are a very dark blue (almost black).
Emotiva XMC-1 & XPA-5, B&W CM9s2, CM8s2, CMC, Hsu VTF-15, Sony BDP-S790 & HX929, Auralic Aries, Apple TV