Dad has a tedder that hasnt been out of the barn for 4-5 years, the reason, his old massey ferguson rake broke and he couldnt get parts. A new rotary rake was cheaper than than a good rollbar rake, so he ended up with a rotary rake ( I beleive it is a Kuhn, but not sure). The rotary will almost stand the grass back up in a windrow, and moves the hay very gently. Instead of tedding he rakes once, then, if he needs to, he rakes again to 'roll' the hay. But usually, one trip across the field is all it takes. As someone else said, if there is ANY wind, it goes right through the very fluffy windrows and does a fine job of drying the hay down. In fact, now that I'm thinking about it, I havent even seen the tedder, may have sold, not sure.
If it was me, get a good rotary and learn to use it correctly, where you drive in the windrow will REALLY affect how the hay is fluffed and if the ground contact hay is now on top. Why maintain two peices of equipment if you can do the job with one.
DuaneW.