I love these threads. They they should be called "How do I ruin the hamdling of my 1/12th (or Sedan) because I am lazy and wont use tape" threads.
O-rings bend your chassis from the tension. This tweaks the heck out of your chassis and makes you car handle bad.
Most people that use carbon straps put them on too tight becuase they crash a lot and want to keep the cells from flying out all the time. This tweaks the heck out of your chassis and makes you crash more.
There is a reason why pros use tape...it holds the cells in better and does not tweak you chassis.