I ordered some OEM brake pads and using the helpful threads in the FAQ/Maintenance section decided to tackle the job. Its easy thanks to the many posts with pictures and the YouTube videos.

My rears were replaced at 46,000 miles and now, at 122,400 miles, they are at 3/16 (4.7 mm) or about half way gone. I figure at .8 mm per year wear (calculated from when they were measured last at 108,000 miles) I can go to 3 mm in another 20,000 miles or in other words ~ 100,000 miles on a set of rear brake pads. Wow.

My fronts were replaced at 39,000 miles and were down to about 3.00 mm so I replaced them. 83,000 miles on those pads.

My driving style is real gentle and with mostly rural roads so my pads will last a lot longer than if I drove a lot in stop and go traffic.
By the way, I added at little dab of permatex ultra high temp ceramic grease on both sides of the inner shim and the brakes are silent.
As Johnhav430 posted recently, you need to take your time and be careful with the reinstallation of the tires to finger tight so that the lug nuts are on there correctly. or else they can work loose and you have major safety problem lurking.