Yes, I've done low-angle and high-angle.

IMO, most FF's would be much better served to become competent at vehicle extraction and low-angle rescue. High-angle rescue techniques take a LOT of constant training to maintain proficiency with the technical gear, and the number of times I've used it has been... zero.

Low-angle stuff we do several times a year, with people who have driven cars off of mountain roads and down into creekbeds, etc. and now we have to pull up a Stokes litter with a patient on a board carried by a team of four guys on a rope and a belay.