JWP,
The fly weight of the SL-2 is 21 oz. The Sl-3 is 23 oz. So for 10% more weight you get 30% more space and a shelter that will shed the wind much better, plus you'll only have one pole in the SL-3 to work around compared to the 2 in the SL-2. I've owned both models and much prefer the SL-3, but I much prefer the SL-5 at 29 oz over both of them. Twice the space of the SL-2 and I can stand up in the very center of the SL-5. So thats the only one I own now
