So the question becomes, is there any real advantage of having a push up mainsail ?

Wouter [/quote]

Absolutely, it looks good to non cat sailors who wonder how you are going to get your sail up the mast.

Plus I find the push up sails easier to get down.

Another advantage (which Wouter sees as disadvantage) is that the tube doesn't allow you to roll up the sail too tight. Rolling too tight really doesn't help the sail I think longevity wise.