Advanced V.G. on the saturn is ok. It has great music, but I don't care for the hit detection. Honestly, Super V.G. for the super famicom has better hit detection.
I would try to pick up advanced V.G. 2 for the psx. I have never played it, but the presentation looks leagues above the predecesors. There is a super bar/better graphics/ etc. Sure these are shallow novelties but it might be worth taking the chance on that game because most likely you will be dissapointed with saturn advanced V.G.
Asuka 120%(burning fest excellent) is alot of fun for psx. However I heard that the saturn port has better animation resolution. The saturn port (burning fest limited?) may be less expensive as well.
Asuka plays better out of the two. Asuka is a real dial a combo fest as posted above. The game is a juggle fest as well. Advanced V.G. has the pre "combos are all the rage" feeling to it. You can find some links and two in ones but nothing fancy..or broken as far as I know. Advanced V.G. has it's charm but you would be better off buying Asuka 120%.