For those of you who have used an ID sil shelter, what is the effective length? I've seen the numbers on the ID website, but they only give overall length, not effective length. By effective length, I mean something like the distance from the pole to the end of the shelter. Better yet, from the pole to the point where a sleeping bag would touch against the fabric. The length, of course, is going to be partly determined by how high the shelter is set up and how low to the ground the edges are staked. I really like the idea of Henry Shire's tents, but at 93" they don't improve on what I have already. I've looked into a couple of catenary cut tarps that seem long enough, but am not entirely satisified with those either.