Nice choice 7mag, we really love our golite tipis! There isn't too much difference between the SL3 and SL5 except interior space...When Luke and I backpack together we typically choose the 5 for more space, but the SL3 sleeps two and some gear comfortably and is a palace for one person! In fact we will take both shelters along on our upcoming Dall sheep hunt, the 5 will be our primary shelter and the 3 will be the emergency shelter in case of unplanned bivy out overnight, or to get out of foul weather for lunch some afternoons. We ditch the center pole and erect the shelter with trekking poles to save weight, and I would plan on adding cord to the option guy out points to make the shelter even hardier if the wind kicks up.
If you haven't seen them already, check the videos page for footage of ours in action. Luke did a full video review of the SL5, and you can also see the SL3 in the "solo slog" video...
Congrats again on the shelter, you won't be disappointed!