I've lived in Petawawa/Pembroke for the past year. We've never lived in the q's but have friends who do, and they're really not that bad. They are undertaking an upgrading plan and some of the q's have already undergone some renovations. North side is definitely better than the south in many respects. The q's seem to be in better condition and there are more amenities.
Another advantage of the north side is the RecPlex, theatre, skating rink and Dundonald Hall (gym, pool, gymnastics for the kiddies, sports teams for you, etc) are right there. I don't have kids so I can't comment on that situation, although there appear to be plenty of them around. If your wife wants to work, this is a good time to be coming to the area. There are several new stores that have opened recently (chicken chicken, liquidation world) and new businesses coming soon (more jobs at the new call centre, home depot and shopper's drugmart - these are all in Pembroke, which is a 20 min drive). Office jobs are tough to come by, but the PMFRC is always willing to help.
In general, Petawawa is a nice town for a young family. The young, single guys don't seem to be huge fans, but I've enjoyed it here so far.
There is a grocery store in Pet other than the Canex, but the two "malls", theatre, discount grocers, etc. are in Pembroke. All in all, Petawawa is a nice little town. It has what you need and Ottawa is close enough (a little over an hour on the highway) to get what you want.