Why thank you Terry big *alls!!!!
I occasionally use a Schwabisch/distal. They are certainly a big improvement over a Blake's, but not the Vt.
The Vt/Mt has two disadvantages, besides being finicky (sensitive to length, rope type, and slding possiblility after bunching up)
1: When using lifeline as second lanyard, the lie will slide to its end, so if you want a preset length to toss up, a stooper knot must be tied- a minor inconvenience.
2: You can't body thrust with it. No problem for short pitches, just hand over hand above the knot, then reach down and quickly feed slack out.
BUT Guess what, you can bodythrust with it, and here is how:
Use Mark Adams adjustable self advancing bridge (from recent Arborist News, I think), and use a Petzl Fixe as Vt pulley. get a mini pear snap~ 1 inch long, and a short length of throw line size line to prussic around the rope's bitter end. Clip around bridge of the fixe, set prussic just so, set life support prussic below it near bitter end at harness, adjust it so Vt is just out of reach, and thrust or footlock away.
Back to the so called attention needed to use a Vt, I know of no problems with all the folks I know using it.
Nothing could be finer, than to be in he* ******......
..in the mornin'........
.......uh oh........oops