My recumbent road bike has front and rear suspension. After riding a similar bike without suspension a couple times, I don't know if I would want one without. On a bent, I can't stand to avoid the bad bumps. I don't think the suspension adds more than a 1.5 lbs, and that's mostly the shock in the rear.

Also, being able to put air in or take a little air out when I know I'll be going on a specific route is a nice feature of the air shocks specifically.

My velo has spring shocks on the front wheels (not easily adjustable) and an air shock on the rear.