I've used both the OMP Cool Line and Alpinestars balaclavas. I use them more for comfort and second, they tend to keep my helmet marginally drier (i.e. quicker to air out).
The Alpinestars ZX one has a small opening for the mouth if you use an integrated drinking system, whereas the OMP one doesn't.
I find the OMP one slightly more comfortable though as it isn't as stretchy as the Alpinestars one.
I've used both with my Stilo helmet with no problems being able to communicate via radio with either on.
Last edited by sawzall; 05-08-2013 at 11:53 PM.