Growing up in Hamilton, the Accies derby was always more important. Play a team 3 or 4 times a season, however, and it stops becoming such a big deal.
As for Airdrie, I'm amazed at how people easily accept them as the real deal after they were liquidated and came back only via the Clydebank / Airdrie Utd route. That's the kind of thinking that let NewRangers convince the media they are OldRangers.