With the bike shop all backed up with bikes to repair I decided to try to replace my own brake pads. I watched a couple youtube videos to figure out how to do it and all went fine. I now have new brake pads and feel empowered to do more of my own repairs and maintenance.
I use Avid JuicyBB7 Disk Brake Pads on my Volagi Liscio & Trek Portland. I can break with much more finesse i.e. don't over or under brake. Perfect on wet Portland streets. Also a big plus on a huge downhill run where caliper brakes are smoking and overheating the rims, the disk brakes have no probs.
These brake pads are use on the parking brake (rear wheel) of my recumbent trike. Therefore, they will not get as much wear as normal brake pads. I expect them to last a very long time-barring any chipping or damage. They are very easy to install.