If a non rotary pilot might stick his head around the door...
Firstly the Alpha is very expensive (about £600) but a really comfortable and strong piece of kit. I got to wear one once or twice in a FJ, and for maintaining lookout during high g manoeuvring, they're unbeatable. I'd certainly invest in one if I did much aerobatics.
I spend much of my life climbing in and out of various aircraft, some of which are open cockpit, some not, and some too cramped to accomodate a bonedome (which I've been rather unhappy about on several occasions). I use a combination system from "Communica", a British company. it consists of headsets, helmets which fit over the headsets, and removable locking clear visors. So, for most circumstances and types, I'm covered.
I think other companies, such as Lynx and Airzone do similar systems, although I think Lynx is probably the only one with a BS kitemark for helmet integrity. The helmets usually will also work with a number of other headset types, which is just as well since some of the plugs used on this kit (which is generally designed for microlight use) are pretty non-standard.
It's a good compromise, that works for me anyway.
G