SHA is a fine airport as far as transitting, and probably better from a food option perspective on the concourse. The lounges aren't great at either airport while flying Skyteam. I would say the main issue at SHA is that, in my experience, delays can be much worse. I've been delayed for 8 hours before, and can't ever remember departing on schedule. PVG isn't necessarily 'on-time', but seems to be a little better. Others may offer a different opinion.