I have spent huge amounts of time commuting to Shijiazhuang for business since day 1 of my China stay so I have seen that city evolve before my eyes.. it's a strange one!
Yes, it was one heavy mecca of smog and industrial pollution back in the days but it has gotten much better. The government has gone far and beyond in their efforts to clean up the city but they still got work to do.
It's gigantic and half developed with 5 star hotels, bars, discos and plenty of other amenities that can appeal to foreigners but it is very much a Chinese city.
It takes 2 hours on a D train to get to Beijing which is also a big plus for a day trip of shopping and what not.
One thing to remember is that it is the Capital of Hebei and the local government is quite paranoid. Hebei has the most stringent visa requirements and they're extremely weary of foreigners in the city after the milk scandal that took place there.
I still go about once a month and I love those trips, they're my "Chinese Weekends" as I call them with Baijiu, bathhouses, KTV and just plain old fun sitting on a street corner munching on chuan'r with a little erguoto