So I went to trap tonight and did a little better, although somewhat inconsistent. My first round with the 8 1/2 shot was a 19, but then I decided to try something and I switched to a full choke instead of the modified that I usually use. I ended up with a couple rounds in the 14 range, but the clays I hit were very solid hits.
I think I'm going to stick with the full choke and the lighter loads for a while - it will force me to be a better shot and really work on my form instead of just standing up there being satisfied with a 22 or 23 (which is what I have been hitting when I shoot 7 1/2 with the modified).