i stayed at santa clara last night, i book under G2 promotion.
when check out, i told them i want to use my hyatt check certificate to pay for the room. However, they said since g2 promotion require prepaid payment, they have already charge to my credit card, so I couldn't use the hyatt check.
it seems like i won't buy the check because i always book it under g2 or g3, which requires prepaid payment.