Looks like the pads aren't hitting the rotor very square. I installed some new rotors I had laying around and roughed up the pads quite a bit and then went to work on re-setting both the front and the back calipers. The nice thing about Shimano brakes is you can just throw them on and they work with very little adjustment. I just couldn't ever get them to stay working. The Avids are a bit more finicky to set up (at least for me). I think I finally got it though. Initially they both squealed but after riding them around for a while and heating the pads up, they finally shut up. They feel even better now that all of the pad is contacting the rotor too. They should get even better after they get some dirt and water on them and really get seated.
I like the Alma even more now that it's SS. I'm not sure it's a good idea yet but....I like it.