When I first starting riding a little over two years ago, I quickly upgraded from a full face helmet to a modular. I love it, it's very easy to communicate with it on, I can get it on and off over my glasses.
I was recently given one of the 1st generation Fly Trekker D/S helmets. The first generation models were crude, distorted lenses, chin strap way too far back, etc. I still gave it a shot a few times. I thought that the visor was too narrow to be very effective, and it was uncomfortable over 65mph, especially when turning my head. I can see that the abilities to wear goggles would be convenient, air flow in the summer was extremely nice, but overall, I don't ride aggressively enough to justify using one.
I plan on replacing my modular next year (3 year mark) and I am 99% sure I'll be getting another modular. I went on a week long trip this summer with a buddy, me in my modular, he in a full face. He said he's planning on getting a modular before our next big trip. It'd nice to flip it open to get air, chat, and you don't look like a storm trooper when you pull up to the pump.