Submitted: 03-26-2008 by ipaddlepaul
I was interested in Timothy Hladky's comments (12-24-05 review), since my experience is the opposite.
First off, both the T-rex and S1-x are at least 9's. But the T-rex is much much more stable (I am a 5 foot 6 inch 145 pound guy). I paddle about 200 miles a year for the past few decades and go out on all kind of water (ocean, waves, lakes, rivers). I have a Wilderness Systems Shenai (another great boat with a 9, about 18'4" and 18" wide) a S1-x, and also a thunderbolt (T-Rex).
The S1-x has got to be the most beautiful, and the Shenai, is very fast for a very stable boat even in 6 foot waves. The T-Rex however is the fastest and much more stable than the S1-x. For me, I cannot use the S1-x when there are even minimal waves unless the water is clean, since I can count on swimming once or twice when I get tired. I can't go full speed and can't use a wing paddle also due to balance and control issues. The T-Rex (west side boat shop) has a seat on the floor and the legs are not bent. This means that the center of gravity is very much lower, and means you can use your legs to help with the paddling. It isn't beautiful but it is amazingly fast and I don't mind when speed boats pass. I have never gone swimming.
T-Rex has the problem that if I were to exit, it would fill with water and be very hard to recover (no bulkheads). Having said that, I have rolled it for practice (you barely need a paddle). The S1-x is very easy to re-enter when you fall off (lucky for me).