I recently replaced the strut and spring assemblues on my 2016 Expedition EL (100K miles) with the KYB Strut-Plus assemblies. They have been on for about 2 months and love them so far. The original struts were really worn and the KYBs restored the ride to original. I decided to install the ReadyLift 3/2 lift and leveling kit on top of the KYBs and it made the ride height look awesome. I was able to fit 35" BFGs on with the lift too.
I previously installed the Monroe Quick Struts on a 2008 Expedition regular wheelbase that I used to have and they were pretty good too. Had them on for about a year and a half before I sold the truck and they seemed to hold up well.
Between the two, I would recommend the KYBs as they do a great job of restoring the ride quality pretty much to the original factory ride. I couldn't be happier with them, and my truck rides like new (not to mention the couple of inches of ride height that I gained).
As far as installation, I did it myself and it wasn't too hard. I have done this type of work twice before but am not an expert by any means. The ReadyLift website has a great video on how to install the lift, and in the course of doing so it shows how to remove the front and rear coil assemblies and reinstall them, so that video is useful even if you are not installing the lift since the same steps are followed (excluding the spacer installation). Took about 6 to 8 hours to replace all 4, was able to do it by myself with normal tools, but be sure you have 3 ton jack stands, a breaker bar to break the torque on some of the larger nuts and bolts, and 2 floor jacks (I have a 3 ton floor jack and used the spare tire jack from the truck as the second and that worked fine).
Hope that helps. Good luck!