I just saw Austin Homebrew advertise they are doing Crystal 150L for only $1 / lb right now. I'm working on my own oatmeal stout recipe and was going to put 10 oz of Crystal 80L in it. Do you see any issue using 150L instead? I'm not real familiar with the taste differences. Sounds like it will have a little more caramel flavor, that's all I know. Since this is only 6% of my grain total, I figure it may be worth trying.