When looking for gutter covers, start with what you are looking to keep out of the gutter system. If you just need to keep leafs out you may just need a simple gutter screen. If you have pine needles than you may need to spend more money on a micro screen cover to keep out the smaller debris.
Depending on what your problem may be do as much research as possible because as a gutter contractor we find most of the product warranties on covers do not cover much. When we meet with you will give you many options along with the pros and cons of the covers we offer. After educating you on the covers at that point you can pick the cover that best fit your needs and budget.
Installed like the screen, the micro screen has an added stainless steel mesh over the louvered cover to keep out smaller debris. Because the cover is a lot tighter we have found in some cases water skipping across the cover in high volume areas like inside corners. We have also had issues with slushy snow clogging up the cover causing some water to drip over. Now if you don't clean your gutters this problem will be a lot worst. It depends on how you look at it with a micro cover less heavy wet snow can get in the gutter stopping the chances of gutters of freezing up. If you have a lot of pine trees this is the cover to use it will not let them through the cover.
The most basic of all our gutter covers and sometimes the least problematic. This is least expensive and very easy to install with our gutter system. The cover screws down to the front lip of the gutter with 1/2 stainless zip screws. The cover comes in four foot sections and it's perforated ideal for keeping out leafs and twigs. We have had customers use it in the past with a light amount of pine needles but we have seen it fail over time if too many pine needles land on it.