Not trying to psyche anyone out, just being realistic about this run and some possible differences between it and a R2R2R...just some food for thought for those considering it.
From what I've looked at on maps, it strikes me that you better be a bit more on your game on this one. You can't get lost on a R2R2R and you have anywhere in the first 20 miles to turn back if you're not feeling it. With the TZ being point to point, you sort of have to finish the whole enchilada, or at minimum make it 50K to the Grotto. In addition, while it's a marked trail system, there are FAR more opportunities to make a wrong turn or take a side canyon. I also suspect there's less human traffic than in the canyon in many spots. Due to likely having to shuttle all the way to Lee's Pass on the morning of the run, we might have to start later, basically guaranteeing the back of the packer's will be out well past dark.
Despite our crazy weather on the R2R2R, it seems a good mapset/navigation tools (which I didn't even carry in the canyon) and emergency kit are far more necessary on this one.
If you haven't already checked it out, Skurka has a great mapset ready to download for this route- only drawback for me is that it doesn't include UTM coordinates. I'd likely want to carry a simple GPS on this run just in case.