Indeed, that all new Legacy complete kits can now include the wing cuffs at no charge, indicates a definite interest in this area. As an upgrade, the cuffs cost $1495. And a quick online search also reveals support for this modification.
One of our members, John Smith, has written an article explaining his investigations about wing cuffs, an explanation of what they achieve, and why he elected to include them on his Legacy.
“Before I made a final decision to build a Lancair Legacy, I talked with many people to find out as much as I could about this aircraft. The range of opinions and advice was massive, and without going into all that here, one area that I resolved to research was around systems and passive devices that might help to improve flight safety.
…If you’re not familiar with what a wing cuff is, you might be wondering what all this fuss is about! In a nutshell, a wing cuff is a drooped leading edge section fitted to outboard wing sections covering typically around 30 – 40% of wing span…” John Smith
Discussions on the pros and cons of wing cuffs will probably continue – indeed, it has recently (2013) been discussed on the Lancair mailing list.
Those interested in reading more should access John’s article, Wing Cuffs on the Legacy.
Members might like to add their own experiences in comments here.