I donīt know which one is the best, but MSA Gallet LH350 is definitively the most expensive (maybe double than Gentex). Itīs not worth that.
I have both, the old good Gentex SPH and Gallet LH350. We bought LH350 because of dual-impendance switch (low and high), the helmet is really state-of-art, light, fantastic visors (yellow for fog, and dark-green for sun), good hearing protection, rear carrier for NVG battery... Personally Iīm very satisfy with it.
But - it is not so comfortable as Gentex. Shell is not flexible and it seems to me, smaller than standard. Half of pilots donīt like them because of that and complain about that.
My suggestion is, try before buying. And if you buy Gallet LH350 be careful with M-size ...very tiny
! Rather buy L-size.
...or, rather buy Gentex!
JR