No, never installed one.
Before you do, here's a few things to think about;
They do not provide a suitable ground plane. That won't stop the antenna from working, but it'll work better with a proper ground plane under the antenna. While these can make installation easy, they are a compromise mounting solution.
While they have multiple holes in them, you don't want to install several antennas side by side on these, even though the manufacturer mentions doing exactly that. Ideally, this would have one hole right in the center. Spacing multiple antennas that close together would be an RF nightmare if any transmitting was done. Even if receive/scanner only, close antennas can detune the antenna and throw off the radiation pattern.
The 1/2" hole size is an odd choice. Industry standard NMO mounts use 3/4" holes. You can purchase mounts that will do 3/8" holes. So if you use an NMO mount (and you should), you'll either have to drill one hole out, or play with some sloppiness in the mount.
You need to consider coax routing. How are you going to get the coax inside the vehicle? This bracket doesn't solve that issue.
You need to pay very close attention to waterproofing. Some of these style mounts are known to leak and you'll get a puddle in the back of your cab.
If you do go with an NMO mount, you need to make sure you get the type that has the enclosed underside. Standard NMO mounts will leave the bare conductor exposed.
I always recommend drilling the hole as that will solve the ground plane and waterproofing issues. If that is 100% out of the question, then go with a fender bracket. That'll be less expensive and probably save you some long term issues.
