Hi Ray and welcome
I've no idea whether you've done any miles with an open face in the UK or what and I can only make a general guess that if they're EU tested then they're probably legal, but I would make a couple of observations based on many miles wearing open face helmets.
I've got three full face helmets and probably half a dozen open face ones and the wind noise from the open facers is horrible over about 30mph. OK round town but it would drive you mad over any distance. I used one on a trip to The Gambia on the basis that a ff would be too hot in the desert and found myself cruising slower and slower because of the noise.
The other thing is face protection. Not so much for when you highside into a pile of gravel, important though that is, but when insects etc hit you. The bl**dy things hurt. I found myself riding along with with my hand in front of my face going through a locust swarm in Western Sahara and they even hurt my gloved hand when they hit. OK, not too many of those in France but even flies hurt at 60mph. Old time bikers, pre full face helmets, would use goggles and leather face masks for good reason.
Last edited by backofbeyond; 25 May 2010 at 14:10.
Reason: Mind fuddled from wearing open face helmet