Double grind - lets talk chisels

I have been interested in a ciuple of chisel threads currently. Some well thought out input.

Recently i have seen some Americans using a double grind on their chisels.

1) They have a micro bevel (done free hand without using a rest)

2) the major grind also done free hand is a convex grind

One of the guys who does this promotes shear cutting i think it was. He starts sanding at about 400.

a) My question is others views of this?
b) Have / would you try this?
c) As mentioned by Hughie in another thread .... aussie timbers are hard. Would this work on our timbers?
d) an observation for comment rather than a question. It seems the grinds are not particularly repeatable.

I will try and access my youtube library and post a link to one of these guys

Thanks in advance

Dave TTC
Turning Wood Into Art