No, but my wife and I are heading over in mid April for a week. I've talked to several folks about this fishery...in particular was a group I met on Rock Creek last year and they really talked it up. I've called ArkAnglers, Royal Gorge and one other fly shop (whose name I don't recall) about the fishery and timing. They say from 4/15 through 5/15 is prime time and even if you hit some run-off, you can find action somewhere along the 80+ miles of fishable water....much of which is public access. The "tax day" hatch starts around Cannon City and moves 7-10 miles upstream each day.
We will stay in Canon City our first couple of nights, then head towards Salida and eventually make our way over to the South Platte as we head back to Denver for a return flight. I'm psyched about the trip and hope to witness what is described as a caddis blitz rarely seen on any other river.
My only other trip to Colorado was part of a business trip in late February some years back. The week before I left, it was "blue-bird" weather and the Deckers area was on fire. As luck would have it, a weather system moved in and it never got over 5F the week I was there...ice-off had no effect!
I'm certain this trip will be better. Have fun and we'll probably pass you on the river.