The best plug I've found, so far(I haven't used Thunderbolts, etc.), for overally use, is the OS #6 (old A3). It is a hot plug, and maybe that seems to work best for me, both in CL and "dark side" flying. A problem I've had with the Fox RC Long is that, especially on a profile, using a "hang on" lighter, the electrode will loosen up and cause a compression leak and weak burn. Just my opinion.
Glen Wearden