I've done several trips with my wife.  Our 1st together was just the two of us and trips since have been with other couples.  I firmly echo what db said about couples trips being lots of fun.  My wife and I have very different paces.  Mrs. Snow Dog goes on vacation to relax  :o :o :o while when I head into the woods I tend to be a little more "driven".  Oddly enough, this is the opposite of our personalities at home where she's the Type A and I'm more relaxed.  Also, while she likes to fish, she's not quite as hardcore about it as I am.  Going with another couple allows us to each to enjoy the vacation a bit more.  When she wants to relax or lounge around camp, generally the other wife is of the same mind so us guys will go out and do a little more fishing/exploring.  Also, she's ready to head home after 4 days or so and I'm just getting warmed up good by that point!  We have agreed that any future trips will be a bit shorter than our usual 8-9 days.

Unfortunately it's been several years since Mrs. Snow Dog and I have tripped together.  She went yearly with me until we started our family, but hasn't been back since.  Someday I will get her and the kids out there again, but it will certainly be a very different style of trip than my usual.