I use a David Clarke's helmet in the Pitts. The instrument panel is full of sharp protrusions that would easily break facial bones and skull if one were to impact it in a bad landing!
Of two Pitts crashes that I have first hand knowledge of, the first chap fractured his skull and the altimeter setting knob penetrated his forehead. He died.
The second fractured all the bones in his face and broke his jaw after "kissing" the instrument panel. He survived but is brain damaged. Neither were wearing helmets.
The helmet might just lessen those injuries in a similar situation.
Go to any aerobatic comp and the majority of competitors wear some form of head protection.
Sometimes for convenience I've used the helmet in other aeroplanes instead of a spare pair of DC's but it is never worried me how "silly it might look". many say that I look silly enough without anu additional paraphenalia.
Stik