My son was gifted a Scott 9' 5wt and we're looking for the right line to match it with. Right now he's using a traditional 5wt double taper and it is working okay for him, but is a little finicky about the anchor and sometimes loses enough steam to get nice turnover. He primarily uses spey casts, and only occasionally overhead casts. He swings wets and small unweighted streamers for trout, but also wants to retain the ability to fish upstream dry flies without switching lines. I'm torn between the Rio Single Hand Spey and the Airflo 40 plus. Anyone cast both lines? Which do you prefer and why?