Thanks for all the input, thats alot of information.
I think realistically we will probably only get the time to do one park which makes this decision quite hard, Gillroy and Santa Cruz sound great for atmosphere but the temptation of Six Flags DK and Great America for big rides is just too much, Medusa and Top Gun (sorry, flight deck) both sound great at either park, i'm a big fan of B&M Coasters and would like to try out some of these. Think my real priorities are becoming clear now, atmosphere would be great, B&M coasters would be better
So Six flags or Great America?
Might be able to squeeze in a trip down Route 17 to Santa Cruz anyway on top of this, but its a time thing really, won't know until we are there, but for sure either Six flags or Great America?