Not planning on rappeling with the harness - I would only need it for a lift/short ascend (over small obstacles for my old pal).
What I like about this harness (apart from being safety tested) is that: it seems easy on/off (it has buckles and than when lifting you attact to metal rings (so no pressure on buckles)), and has a lot of paded under chest part...
I was looking at the webmaster harness but it doesn't seem padded enough for my liking - it only has straps under chest and belly.
As for the double-back - I do think it has suffiecient padding but I am affraid that it could get a bit hot?
Also as per the video I think it would be PITA to put it on a longhaired dog (which mine is)...
But thank you in any case and I am also open to other suggestions of insertion harnesses