I towed my utility trailer with 2800lbs of quickcrete in it.
I was very careful to balance the load juuuust a little heavy toward the tongue to keep the tongue weight light (around 300).
I did notice the push on stops, but Mo's brakes worked fine.
She scooted nicely as well.
If I were you I would def get the air bags and baby her up to speed.
A friend of mine who is a big time boater said that eectric brakes on boat trailers were a no-no because of corrosion. He said surge brakes were the way to go on boat trailers. After towing just a short distance with 2800 lbs of concrete I can tell you that in a panic stop going freeway speed with anything weighting more than that would be more than exciting without trailer brakes.
I have towed 6500lbs many times with a suburban and it was a handfull if your brakes weren't dialed up enough. Supreme pucker factor will definitely occur.
