Agreed, an SL3 is pretty much a one man, with a lot of storage for gear. An SL4 is a palace for 2. IIRC, the difference between the two is less than half a pound?
If only using the fly 3oz difference according to their comparison chart
That is probably correct. The difference is the SL3 is a hex/tipi and the SL4/5 is a pyramid. Those corners make room for that second fart sack.
