Just my opinion, but Saturday sounds good for this Rock City place. 3 reasons:
1) If you get wasted Friday night the weekend may well drag on painfully.
2) Saturday night we can start in Bugmans and get filled with beer before going out, which normally lends itself to a better night, and may prove cheaper than club drinking (don't know the 2 venues though).
3) Not sure I'll be there Friday night, and I don't want to miss this!
