I ran one last fall for a day.  I was very impressed.  The price of a new one is a little rich for my taste, but my dealer managed to find me a 2 year old Welger rp435, which is the same thing except for a few minor changes (camless pickup on the 504, etc.).  We've just got a good start on haying this year, and so far the Welger is doing everything I had hoped for.  It definitely outperforms the old br740A.