I flat tow 4 down.
The only thing I would add about dolly towing for you to consider is I have been at many CG's where they don't allow you to leave the dolly on your CG site. Albiet Of course there are just as many that don't care.But it is something to consider when deciding which way is less of a hassle.
When they don't allow the dolly at your site, that means you have to park the dolly behind the CG office or where ever they say for you to put it. And all the ones I've seen you just can't pull your car in to load it you have to drag it out by hand and load on the road.
That and on small sites, having the dolly parked on the grass where your eating/bbg area is located is sometimes a pain.
I have also watched many RV'ers getting ready to leave and struggling to get the car aligned and on, and tires ratcheted down etc. All I have to do is hook up two pins and plug in a few wires and plugs and I am gone!