I'm all for them when the basis is in your favor.

Just don't sign one when the basis is bad. 

That's all.

And yes, I wouldn't call it a bad experience but rather a learning experience: in 2005? I had 35 acres of corn. (never had corn before) Hired neighbors to plant and harvest.  I had asked a private elevator if they had room for my corn and they said yes.  I didn't find out till after it was delivered that they would only do a basis contract.  Corn was $1.59 when it was delivered to the elevator which had a $-.69 negative basis.  I gave the crop away and learned what a basis contract was and when not to do one.  Corn was an afterthought that year but got my feet wet.