I was quite disappointed by the VR Missions disc - you gain nothing by getting 100% completion, even with 1st, 2nd and 3rd place in everything. You just get a brief picture of a schematic of MG Ray.
Also, having the Replay Theatre removed from the international version was a bit of a downer, along with the extremely limited 'ninja' mode.
The disc is utterly useless on the PS2, which is most definitely teh suxor - there's a lot of fun stuff there (in spite of the criticisms I gave above), but it's now useless because the PS2 can't cope with some disc-swaps.