I just fished the X 591-4 for a day in MT and couldn't be happier: it cast short and long accurately and mended a WF5F old style Rio Grand (1/2 size heavy) beautifully in fast water and frog water. I never got a feel for my 591-4 One and am glad it is sold.
If anyone is interested, I'm selling a new, never fished 691-4 X with the factory tube, sock, and warranty card. $615 shipped to the lower 48. $600 if picked up in Bend, OR. Shipping to Canada, AK, and HI by arrangement.
Satisfaction gauranteed: notify me within 3 days of delivery and return the within 7 days. If the rod is in the same condition that it was shipped to you, I will refund your purchase price less my original shipping costs.