Hold on ....
You looked at the lens at the dive show and decided not to buy it because of the specs & you can't be bothered by the mount??
I can't make a judgement unless I have first hand use of the item
what difference does th emount make ... absolutely none in my opinion
My composition of the whaleshark is bc that is what the OP mentioned
ok, rhinopia & diver .... whatever, the design of the lens is very very clever and it does what it sets out to achieve, a wonderful effect away from the boring images some people take
My practice TWO dives with crocs, sharks & beer bottles which you have seen is nothing compared with what I have achieved since