Nyal wrote.What is the downside,
other than cost, in using such a device?

Don't know of a down side, Nyle, but I know of a great big Positive side. I
watched a tow rope catch the wing tip of a glider waiting to launch. Spun it
around and the wing hit the pilot in the back. Only reason this pilot wasn't
killed was because she was wearing a parachute which took the impact. Dangling
ropes are dangerous. All the FBO's where I fly use take-up reels.
JJ Sinclair