I've got a few questions. 1) Whats the difference between single prong & double prong? I assume that the double prong feels more stiff and offers more support, but is it just a personal preference or is one actually better? 2) Are the "Power Up 4" Power Belts" from Bodybuilding.com any different than the product that EFS sells? 3) Does anybody have experience with ordering from bb.com? 4) Any other suggestions to keep in mind? 5) Also, If I had a 33-34" waist, which belt on EFS would you go with? edit: the power up 4" belts are out of stock anyways, so I'm looking for more suggestions on where I can save money, but still get a quality belt? Should I just shell out the extra cash and go with EFS?