@Julian, I actually just purchased the Filmcity version like that. I got that one simply because it had a lens support on it already (and it was red :P). I did buy a second tripod collar though as you mentioned. Please do open a thread, I'd like to see what your experience with that system is like. Once I receive mine, I'll gladly add to it.
@tferradans, I have been reading that thread (on my second go as I skimmed through the first time). Maybe I missed it, but was the math or reason as to why you choose +0.5, etc ever covered?
Out of curiosity do any of you guys know the use of the backup lens? Does it have a practical use for dslr owners (if not, no worries, it's weight makes it a fantastic paper weight or book-end).