Our house is in a pine forest. If I didn't clean the gutters at least once a month, they were rendered useless by all the pine needles and pine cones. From the research I did, it sounded like no gutter system could cope with pine needles, and once it clogged, it was very hard to clean them. I read the reviews on the gutter brush, and I honestly didn't have high hopes. I bought enough to do the gutters that were the worst, and tested it out for a year. Wow! The whole time, the gutters kept flowing! Yes, pine needles get stuck in the gutter brush and form a layer on top of it that doesn't look very nice, but the water can still flow freely in the gutters and I no longer have issues with water damage from overflowing gutters. Instalation is super easy. Once you've cleaned the gutters, you can easily do a whole house in under 2 hours. If you need to pull them out to clean them, that's easy too. Just pull them out, shake them, and put them back in. It's not something I'd do too frequently though, because the bristles that are compressed by the gutter supports stay permanently bent after being that way for a year. All in all, these have worked great for me, and far surpassed my expectations! For reference, after my year long experiment, I ordered gutter brushes for the rest of the house. While the gutters that had the gutter brush were still flowing freely a year later, I removed 8 5-gallon buckets of pine needles and pine cones out of the gutters that did not have the gutter brush!!! Some people won't like the fact that you can see the top of the bristles and debris that gets trapped on top of them, but I don't care as long as the gutters keep working. In any case, it's still a lot easier to put a brush on an extension pole and brush the debris off while still standing on the ground if it bothers you that much. Overall, I'd highly recommend this product to anyone who is more concerned with function over looks.
The above is a verified review currently available for viewing on Amazon linked from FAQ about pine needles.