I have two of these speakers in my Mercedes E350 in a custom box I built myself, and I have one in a custom box built into a 2015 Jeep Wrangler. These are excellent speakers when space is at a premium. To get the best sound, these shallow mount speakers require 0.84 Cubic Feet of airspace in a sealed box, which is easy to get. For those not familiar with building your own enclosures, this means that these speakers will perform at their peak in a sealed box that is 16 inches by 16 inches by 5.7 inches (some other variables are important, but you get the idea). When you are looking to get great sound in a small area, and without worrying about how for the speaker's excursion could impact the installation, these are excellent.
As for sound quality, they have an great low end sound with stated frequency response down to 22 Hz. Also, you can get this speaker in both a 2 Ohm and 4 Ohm version, giving you options for how you want to link these with an appropriate amplifier. In my Mercedes, I have two 4 Ohm speakers wired in parallel (for a 2 ohm load), with each in its own sealed portion of the enclosure. This is run by a Kenwood KAC-9106D that drives both speakers nicely. In my Jeep, I have only one of the 2 ohm speakers run by an Alpine MRV-M500. Both of these amps drive the load very well without distortion.
Hope this helps you with your search!
Pros: Small size requirement for mounting, and small box required to get optimal airspace for sound. Drives with relatively low amplifier requirements.
Cons: My complaints about this are small, but I do wish that the speaker came with a paper template for measuring your hole cutout, and it is a bit ridiculous that the speaker doesn't include mounting screws.