alright. ive got another question about spearguns. i think i have decided on either a 100cm rob allen, or a 100cm Omer Alluminum. now, the RA is offered with either a single 20mm band or twin 16mm bands. the omer is standard with an 18mm power band. which one is best? what are the advantages/disadvantages of a single 20mm (or 18mm) to twin 16mm bands? thanks for the help.