I posted something on this on the buy/sell board, but I'm also posting here as it seems more appropriate on this board. So apologies for the double post.
After spending a week on two Americans 1100's and a 1205, I finally got them figured out. In the end, it's what the pros here have been saying all along - very light tension from the top of the keyway.
Because these are Americans, there are a lot of serrated pins, and it took me a while to get used to them. I know (only because I took it apart) that the 1205 also has a few spool pins. But here's what I found interesting - when I pick the locks, it's not always clear which pin is a spool and which is serrated. I thought they would feel completely different.
Of course, when I get a false set with the 1205, it's pretty easy then to figure out which pins are spool pins. But sometimes it picks without a false set, and to be honest, lifting a serrated pin doesn't always feel different than lifting a spool pin. So, in the three locks, there are some pins I know are spool, a few more I know are serrated, and the rest I really can't tell. For the 1100's I never got a false set, so I think all the pins are serrated, but you never know.
Finally, I have to say what a great site this is - on my own I don't think I would have opened the locks nearly as quickly as I did. I followed Hallis and Awol's advice, watched some of the videos, and read LockyLew's security pin guide. And with a little practice, that did the trick.
Now I gotta get more locks.