I performed 'Insomnia' for my magic buds when it first came out to mess with their heads. One of the costs of becoming a knowledged magician is the fact that you lose the ability to be amazed by many effects, which sadly is what drove our original passion in the first place, so they really enjoyed it.
As far as laypeople go, amazement is amazement. Whether the ropes grow to equal lengths, shrink to different lengths, magically grow knots, etc., like I said, amazement is amazement. It's a good trick to know for it's variation.
Another variation to the Professor's Nightmare is a trick by Jari Santala called
'Magicians Nightmare'. I know Hank Lee's Magic Factory has it http://www.magicfact.com
There's even a demo of it on his 'Hanky Vision' page.
Magically, Jack :bigsmile: