Mark, I have recruited now for over 15 years and I don't know....
that you can say that without knowing some other variables. I have seen people make moves for more money, less travel, more responsibility, etc. and wish they hadn't. I have seen folks accept counter-offers and 5 years later be as happy as can be. That doesn't mean that is all the time, and I always highly caution people regarding counter-offers, however, so much of it depends on the relationship with the management, the culture of the company, the involvement of HR, etc.
In the market-place right now, I would hesitate to make a move for only a 5% raise. I also don't know that I would say Atlanta (some areas) is significantly cheaper than some areas around Philly. It depends on where and they you have to understand the traffic scenario as well. If a sign-on and relo are substantial, you need to find out what the payback period is and is that pro-rated or not? I always tell people that candidates can look great for a day of interviews, but I can help you understand what they will be like as an employee. Similarly, a company could look great for a day of interviews, but it is better if you can network with folks to understand what the culture is like when you are actually employed there.
Having said that, I would still probably make the move - especially since the original poster's wife is on-board. If she didn't want to move to that area, or if she was leaving a fantastic job she enjoyed, I would be much more hesitant. The vacation difference is substantial, and as long as the benefits and potential commute-times are comparable, I believe it would probably be a good move.
I tell every candidate I work with that no-one (including BWI board member or even a wife) can get into the head of the person actually making the decision. No-one knows what they feel at work, or what their relationships are like, or what their future views are on a department, company, etc. Sometimes the decision to others seems so logical, yet it has to come from the original poster as they are going to have to deal with the change. Again, moves are most times more difficult on the spouse (and children if there are any), so if she is on-board I would say go for it.