So, I am careful not to proselytize bents, but this need mentioned here.
One major reason people get into bents are for neck issues. There are very upright bents that completely negate issues, then there are sporty ones that bend the neck the opposite way of a DF, which is (supposed to be) infinitely more natural and better angle.
I thought bents were silly until I tried one. A year after trying one, I'd bought one, 2 years after trying one, I sold my DF. I now own 3, just like DFs there are different styles for different types of rides.

Pros - ergonomics, comfort, aerodynamics are improved (faster on flats and down hills) I'm sure others
Cons - they are harder to transport, they are harder to hang with non bents because the characteristics are different, they are harder to climb with.

If you want sporty something like:
http://bacchettabikes.com/bikes/performance/corsa
The winning men's >50 RAAM 4 man team were riding the high end of this style/brand. They won their class since they were all by themselves, but I'm pretty sure they beat the DF in the same class

If you want a very neutral neck position
http://www.easyracers.com/
these can be as fast as teh above, especially with fairings and body socks.

If you want more info on recumbents than you ever thought you would.
http://www.bentrideronline.com/index.php