Another mount is the ponease. The advantage to that mount is that it attaches to the cam straps and not the tank and therefore is good for traveling and using rental tanks.
A lot depends on your concept and intent. If you want to use it as a possible handoff tank like Tek suggests then slinging it is the way to go. For me, my pony is for me... not to ever be handed off. If someone needs air then they can have my primary or my octo. My pony is just for emergency only....reg failure.....not to extend a fun dive.
It is all how you look at it. And, you have the right to look at it your way.
rich
check out....
www.sea-lutions.com/ponease