I keep meaning to experiment with these. Definitely seems like a solid way to get a high volume of work done with quality reps.
^^^ Very much worth repeating. I've said many times before, learning face-to-face from someone more experienced will trump Internet advice nine times out of ten. Okay, maybe eight times out of ten, but still...
Mike Mahler, Wendler, and Ferruggia (and a handful of other coaches) have all spoken highly of the benefits of higher rep (anywhere from 8-20) deadlifting. If you do the reps deadstop style (standing and resetting grip between each rep, basically treating them like a bunch of singles), you should be able to minimize any potential increased risk of injury.
However, Texas Man, I double-checked your sumo DL form thread from a few months ago and I suggest you focus on technique even more (depending on how you've improved since that vid.) It looked like you were using almost no leg drive. I know you've said you have a knee injury right now, so I'm not sure what you'll be able to handle.