I would do it, honestly I've found I use a helmet allot on the field which sounds silly but it's saved my melon a few times;) I don't need anything crazy but I started wearing one after falling off the bumper of the van on our field. My own fault I was doing something I shouldn't have been and acting like I was 18 again. Either way I got thinking I should wear a helmet, started doing it and most of the time on the field if I'm not in a sniper setup then I've got a helmet on. That said I a painted old school ProTec skate helmet I used to use skating 20 years ago. Works fine, it's comfortable and I figure if it was safe enough for half pipes it's perfectly fine for my knocking my head into stuff;)
But yeah I'd do it, somewhere I've got a legit kevlar helmet forget the model at the moment, but even that is dang heavy for my neck and back anymore on the field. Sure I could run it, but the thing for me is realism is secondary to me being comfortable the next day after playing airsoft;)
So yeah I'd do it;)
Luke