I find it interesting that folks who've never tried something can even bother to comment.
Ah, well, I digress.
I used to use the Wilson Dynalite. I like it alot, and still have it in my kit as a backup. I will limit my comments to my experience in wearing the Wilson Shock FX; I haven't tried any other HSM.
Near the end of last summer season, I took delivery of a Wilson Shock FX. I had tried one on briefly during the summer, and was surprised at how light it was, and the vision was incredible.
I have used the Shock FX for several games, and I really like it. There is no difference (in my experience and use of it) in how and when you would remove it during a play. As far as making notes on a game card, I have actually used the helmet as a small table, while it's tucked under my left arm. I don't find that to be problematic; just the opposite, in fact, it has helped.
I do not wear a hat with mine, though I've read where some guys do, just to "maintain tradition". I tried a hat once, just hanging out at home, but it changed the way it fit, so I go without. I've seen MLB umpires who wear an HSM with no hat; if it's good enough for them at the top level, it's certainly good enough for me at my level.
I haven't noticed any difference in the Shock FX being hotter; (one of the last games I worked it was 90 degrees in game 1; in Game 2, I worked the bases with my usual base hat; let's face it - we wear WOOL hats. I felt equally hot under a wool base hat compared with my Shock FX.
I also haven't noticed anything "noisy" about wearing the Shock FX.
The Shock FX is now my # 1 choice when working the dish. Of course, your mileage may vary. Given the expense of them, I'd recommend trying one before you purchase, if possible.
There's my $0.02.