Yes, Flex has headrests and shoulder belts in all seating spots. The middle of the bench comes from the top of the actual seat instead of the ceiling. That's the least comfortable spot. I've sat in it on long trips, but the ridgid seat belt connectors for that spot and the one next to it are a little under my butt. It's This was a must for me and a huge peeve in my prior vehicle. It does not have the inflatable seat belts-I'd double check if you are looking at new, but the 2010 ones don't. What else...the only spot that does not have a top tether is the rear driver's side. I
the neat techy stuff. In a crash it will unlock the doors, turn on the hazards and honk the horn. It will also call 911 through your cell phone and the Sync system. Back up sensors are standard. The 2nd row has a button to automatically flip and tumble it. We had a hard time deciding between it and the Pilot. In the end, the biggest thing we favored on the Flex was the standard niceties on the basic model that were only on the higher level Pilots.
That said-the Pilot was very nice too. Headrests and shoulder belts in all spots. It's technically an 8 passenger, but I'd say 7 passenger is more realistic to be comfortable. We looked at the Chevy version of the Enclave. I crossed it off the list because of the lack of headrests in both middle spots. That was a must for me, but may not be for everyone.
I'd at least try out the minivans...you might be surprised.