Best route calibration suggestions so far on this thread:
NEB + Braille Book linkup
Snake Dike car-to-car in a day
If you feel good at the end of the day after each of those trips, you have done a few 5.10 cracks and enjoy wider climbing, you are ready for a fun adventure on SS.
For me, lack of general physical conditioning was biggest factor in needing to bivy. And I went really slow on the pitch before the Narrows, too scared to wide stem out above my gear, sapping my strength in armbars and wet fists and groveling too deep inside for security. Whenever I do it again, I think focus on these 2 areas would speed up my SS time dramatically.
I only mention Snake Dike as a measure of your cardio and basic stamina/endurance. If you can do that much work and not feel dead at the end of the day, and you can do the more physical grunty moves of NEB + Braille Book, and you have the skills/experience of some 5.10 cracks, then you are about in the right spot for SS.
Agreed, nothing on Snake Dike or the approach is comparable to SS, except for the amount of calories you burn in a day. SS is still probably worse because of the type of movement, but it's in the right ballpark.
The first time we attempted it, it started raining near the top of the flying butress. We had one fifty meter rope and about 8-9 nuts, a few slings and beaners (minimum free rack). We down climbed virtually the whole route (solo). It was wet. The scariest part for me was'nt the Wilson overhang pitch, but reversing the move that (i think) is the chimney pitch to the 5.8 block at the top of it before the Wilson overhang pitch. Going up you stem an push off your left foot onto your right foot and stick the 5.8 finger lock on the block. Reversing it downclimbing, you have your right finger lock and your right foot on the right wall of the chimney and your left foot & hand on nothing. You have to let go with your right hand and, with just your right foot on the right side of the chimney stick your left foot. And, it is a bit of a reach/stem.
Dave Stutzman had already downclmbed about a half a pitch directly below me in the chimney and standing on a small hold watching me. He saw the expression on my face as I calculated where I would hit (prollie slam into to him as i flew by) and he did his best to squeeze tighter into the crack. It was a sickening feeling letting go of that finger jam, but my left foot stuck. To make it worse I had wore PA's for the first time in my life rather than my EB's because I thought they would be better in chimneys, but they were as slick as all get out, particularly since it was wet.