ooh you made me feel all special! ;-) ah I know who you are now! (not in RL - that would be stalkerish!!)
Yeah I think FC would be awful for commuting. Yanlord is not far from us - its apartment living but I'd say it's the best of apartment living in this area (it's got lovely green grounds and a lot of families). commute (I think) would be a good 30 mins - which wouldn't be unusual for yanlord families I'd say but most kids there would be going to much closer schools (YCIS, SCIS, Livingstone America etc). Having said that, yanlord is more Gubei than Hongqiao so a bit less in the thicks of it than Hongqiao (which is even less city living than FC) - and Minhang really is in the sticks! I think you'd find it a bit of a shock after HK to be honest. I also find that people don't tend to change areas after they've been here for a year or so - most people find they don't want to leave the friends they've made etc.
I'd say Shanghai is going to be very different to HK! I was amazed when I visited a friend in HK that she could walk pretty much everywhere - the distances in Shanghai are much bigger and the traffic can be a little... ahem unpredictable to say the least!
In a nutshell - it might be better for the kids to be near school for the fact that their friends will probably be closer and they will have more space etc but I'd say there is a chance that you won't like it and that's kind of important too!
I'd seriously look at Hongqiao/Gubei area if I were you - the kids may not have many of their classmates around but they will have plenty of other kids to play with and if you have a car it won't be too much of a hardship to do the odd playdate out nearer school.
Are you going to get a chance for another look before you have to decide? There are several compounds in Hongqiao which offer the same sort of space as those in Minhang but more central. drop me a pm if I can help with any specifics - it's a difficult one!
oh one last thing - I haven't done it myself but I have heard that if you call the school they will happily talk to you about bus routes and where the greatest proportion of their kids live - it might give you an idea of where people commute from.