I visited Philly for three days a couple months ago. I thought it was cold, wet, and dreary...and not just because it was cold, wet, and dreary when I went...I just thought it was kind of dreary in general. However, the historic district was cool, the Phillies are getting a new stadium next season which should be sweet, the cheesesteaks were great. All in all, I thought it was okay. Like any big city there's good parts and bad parts.
I live and work near the city and go to school in the city (Temple). Tons of stuff to do, more bars nightclubs, concert venues then you can shake a stick at. Just got back from Lollapalooza at the Tweeter Center across the river in Camden, great show. There's also so much within driving distance. New York of course, but also Atlantic City and the shore, the Poconos if you like skiing, and the fishing and hunting out here is great. Weather sucks during the winter but right now... Eighties during the day and sixties at night aaahhh, I don't miss those 90 degree Houston nights.
I went to college in Philadelphia and can honestly say, the people who responded thoughtfully so far are right on. I wasn't that impressed with the city for the first year or so, but it definitely grows on you. It's not Hawaii, but you get the feeling the people there prefer it that way. It's all about lifestyles, too. In a lot of ways, Philadelphia is like a smaller version of a NYC or London (not like Houston at all, btw), so if she likes London, I can see her liking Philadelphia. Personally, I prefer more open spaces, etc., and won't move back to the east for any permanent amount of time, but I have nothing bad to say about it.
