No doubt a FF is the safest! 20yrs ago i was wearing a $50 Bieffe FF motorcross helmet when i was hit head on by a teenie bopper in a chevette. My chinbar went almost through the windshield about 6" from the top. Needless to say 2 busted lips a bruised nose and chin werent the only facial injuries i would have incurred had i not been wearing it. The center visor snap had a piece of windshield rubber hung in it. Bike totaled, car totaled, i'm still paying the price every day. Ride safe boys and girls, ride safe!

 

I had a Shoei that fit perfect but it degraded over time. I currently have a ZOX out of Canada that is every bit as good as the Shoei, for way cheaper and IS Snell/DOT approved.

 

I mostly wear a 3/4 for riding around our little island especially in summer, but a flip/modular when doing distance in UK: safer than open face, and quieter - a big factor over time at speed from the point of view of fatigue.
Not as safe as a full face, and usually heavier, but much easier at gas stations, having a smoke or drink without having to remove my lid.
As far as fogging goes, get one with a pinlock shield - it really works. I have had a Shoei Multitech and now a Schuberth C3 (REALLY expensive - but the best I tried) and both have provision for sunglasses/specs. Internal sliding sunshield is handy in changable conditions, too.

 

I think a flat black full face helmet looks pretty cool.

 

Commenting on a high quality helmet - Shoei, Arai, Bell (some models).
Pro's:
Safer (some will argue)
Better wind protection
Warmer in cold weather
Better hearing of environment
Better hearing of audio (stock speakers or in helmet)
Less wind noise

Con's:
Hot in summer
Can limit some visibilty
Can be claustrophobic
Takes up more space in bag
Less cool (if it matters to you)

 

Just my two cents. But after I got hit on my bike last year I went full face and I won't look bag regardless of how hot it is.

It's safer period.

Don't be dumb.

I bought a Simpson bandit helmet. They look tough and they are super comfortable.

 

One of the worst days riding was with my modular full face helmet. It was a cold rainy day going over a mountain pass in bad traffic. The visor fogged up bad, I cracked the visor to defog and that opened the upper seal, which resulted in water running down inside the visor. So I had rain drops inside and down my face. Kind of a no win situation, fog or no way to wipe the drops off inside. I always carry my 3/4 with flip down shield if it looks like rain when it's cold as backup. I like the full face when its cold and dry, much warmer.

 

I wound up with the Arai RX-Q, and it fits me well. Schuberth is now coming to the US. They have not really had a presence here, but from what I have read they do make excellent helmets. Nolan has some interesting stuff, especially for those of us who have intercoms/CBs on our bikes. With their N-Com system, it is possible to get a cord so it works with the HD Audio System as well as support BlueTooth for those of you (ok, including me) who want to connect a phone/GPS wirelessly.

 

I wore one for the first time. You may need good ear plugs seems to echo a LOT.

 

I wear a Shark Evoline Series 2 modular. It's very easy to go from 3/4 to full. I tend to go to the full face configuration when on the Interstate or generally going fast - highway speeds of 65+ mph. At slower speeds, I like to go with the chin guard in the open position. On the Shark, the chin guard snaps into place at rear of the helmet. I always have the face shield regardless of which mode I'm using. It's not cheap, but it does offer everything I want in a helmet.