I have done both. IMO, on the inspection level, there isn't much difference. The same level of education, experience and competence exists among inspectors as it does anywhere, meaning some are better than others at any given time. I have seen differences in how the managers/building officials operate, though even there it depends on the character of the individual. Basically, I think that for-profit companies may be a little more inclined to "compromise" on some levels than non-profit. I like compromise, but not based on whether they are in contract negotiations. At times, for-profits may be slightly more inclined to put "sales" over safety.
On the other hand, a private company will generally have far less waste, and even though they are non-profit, there is plenty of budgeting and finance games being played in a gov't. A private company is more inclined to invest back into itself and its services, so they can be better at what they do, while a gov't. may be more inclined to invest those dollars in ramps to nowhere (clever reference to another post!).
All in all, I think they both have pro's and con's, and the quality of each is determined by the individuals. I do think a private can be an awful good asset to a small community without a lot of resources.