Not being "negative", just "real"...here's some points homeowners should look into about Leaf Filter.
Check the warranty. Leaffilter guarantees that the interior of your gutters will not clog but offers no guarantee that their screen will not clog.
Their product completely covers your gutter. Of course nothing will clog the interior...it's covered by the screen. But when the screen clogs (as many complaints indicate) then water will run over.
2. Consumer Reports.
Leaffilter claims to be the #1 rated gutter guard by Consumer Reports.
Look it up yourself. Google "consumer reports gutter guards". Gutter Glove was rated substantially higher. And Consumer Reports had negative comments about all pro installed systems.
Reason of review: Not as described/ advertised.
LeafFilter North Cons: Dishonesty, Product not as promised.