I do own Tonfly Performer helmet (upgraded recently to Speed version). It is light, quiet and fits like a glove (literally, so make sure to get the appropriate size). I am a bit biased with regard to the external altimeter port, since display of my Optima got damaged due to the metal connector strike during opening (rental gear). As long as you are flying canopies with soft link connectors this should not be an issue though. Audible pockets will easily hold Optima or comparable size altimeter. I got >100 jumps on this helmet and still like it.