Just got my i12s out of the basement last week-end for my first ride this year. It was stored flat and deflated on a table.
I must say i'm very satified with the quality of the material used. I bought it almost a year ago (used it 2-3 times per week during the good season) and it still looks great. No change of color, no cracks, no early sign of deterioration. Just a few small surface wrinkles where the boat folds, but nothing to worry and when inflated they're almost invisible.
I'm really, really happy with this boat. The only problem i had is when i sailed in a little too strong winds and i broke the ropes holding the sail. Actually the crimp failed. So i just changed the ropes and used no crimps at all.
great boat !