Maybe you're thinking that since my boat is on Chip's website means that I somehow get a cut out of every sail he sells but nothing could be further from the truth. I was so happy with the way they looked on my boat that I asked him if he would put the pick on his website. Of course he complied

. Seriously though, even though I raced 16's fairly extensively back in my younger days, the only racing I do with my 18 is an occational long distance race out of Ventura to the local islands. I do have to take a "Portsmouth number" hit due to the square top sail now but I could care less. I notice the most difference in performance while upwind sailing. Obviously this is because of the new, flatter sail and would most likely be felt when replacing an old blown out sail with
any newer, flatter sail. I like the Pentax material for its resistance to stretching and basically because of its modern look (sorry, cosmetics are also important to me)
Bottom line is that I had been drueling over the sails pictured on Chip's website for quite some time but couldn't justify the cost until I called him last winter to ask him some questions. He made me an offer I couldn't refuse because of the slower winter season. Whatever you decide, I'm sure you'll be happy with the increased performance of newer sails.
Happy sailing!