Half shell, here.
Just my opinion, and Your Mileage May Vary....
Couple months ago, I decided to try a modular in 2XL, and got a full face in XL for younger Brother Bill.
Amazingly, both fit well.
Felt strange putting them on, but they fit well.
Took us 5 minutes riding two lane highway & backroads to realize: this ain't much fun.
Took us 20 more minutes to realize: this really ain't comfortable.
Took us 30 minutes to realize: these are miserable.
Took us under a minute to find a safe pulloff so we could shuck them off, and strap them onto the bikes.
Never again.
Took me less than a week to sell mine,here.
Still have the other one for sale here, in XL. It's white. Used once for 30.5 minutes. Has an extra tinted faceshield + the clear one it came with.
And the first member here who posts "I'll take it!" here, then PM's me that he will PayPal me a grand total of $20 for shipping it anywhere CONUS is gonna find it at his door, by 1JAN2015.