Been playing with it pretty much my whole 2.5 years on Olympus and I fucking love it. Makes landing in tight spots soooo much easier when you can just tilt your head to see what's underneath you, also helps very much with situational awareness. Also makes a few other games I have much better; X-Plane 11 and Elite:Dangerous both work with it.
A few caveats:
Good posture while playing is a must. If you're a big slouch or like to shift around a bunch, you'll need to change (i.e., improve) your habits.
Takes a bunch of tweaking to get things just right for Arma. Disabling the the XYZ axes (keeping only pitch, yaw, and roll), was a must for me although individual preferences may vary.
You'll need to set up a key to re-center the axis when you do shift position a bit -- for convenience I use middle mouse click. If you're not re-centered properly then you won't get certain scroll wheel options in Arma (e.g., interacting with shops) when you think you should.
Track Clip Pro is a must-have but that's another ~$60 you'll be spending. I tried the baseball cap thing for a week and hated it. The headband on my headset (Corsair, forget which model) is too thick for the track clip so I clip it to the mic bar
It's going to take a week or so until you feel comfortable with it and your muscle memory does its trick -- don't give up if you're not thrilled straight out of the box.