I have incredibly heavy tree cover. i use a version of this http://gutterstuff.com/guttering/
and it works great. Leaves still hang around on top of the gutters between heavy winds, but nothing gets past them, and they do not clog.
Wire screens don't work at all for me, but it's probably due to the type of leaf fall.
Why don't you cover them?
Might last 10 years between cleanings if you cover them, and you don't need expensive solutions either. Wire screen covers sold at big box retailers work great.