Are these comments generally for any racing sails like the Ullman and UK Halsey as well, or is the frailness specific to 3DL?
that's a better question. Do a search on SA for Carbon vs Kevlar and it then gets more interesting. I chose to go with technora, as the fibers don't break down as easily as C or K when being bent, therefore extending the life of the sail. At least that's what they sold me on, we'll see what it looks like in a year or 2. If you take care of 3DLs then you can get roughly 2 years of competative racing out of them. Anything more, and you'll notice you don't point as high, heel a little more, etc, however you'll still have great sails, they just might not get you that extra 0.1 of a knot out of em. 4 years you'll start to get some delam, and 5+ years they may even blow out (not the shape, but the material itself).
Also, you haven't mentioned you're price range? Retail on a technora 155 from Quantum was over $2300 for my 25 footer. But times are tough, and you can talk them into a discount pretty easily right now. Even more so in sept. oct.