It's an okay tour about how whisky is made and all that but not distillery specific. They do however have a good whisky shop. The only reason I mention it is because you don't really have to go out of the way to do it.
You can sample some of the Cadenheads, and lots of other stuff, at the Bow Bar, just off the Mile. Afraid it's just a pub (just a pub!!! ), so I don't know what the gf would think. For god's sake, stay out of Deacon Brodie's!
I have to agree with BruceCrichton. Glenkinchie Distillery was a grand tour. The grounds are very nice and for the meager cost of the tour you get to sample many many whiskies in their bar at the end. At least that was my experiance two years ago. Have a grand time.