I'm doing a 1 gallon batch of stout (well, stout-esque, anyhow...) -- the wort is boiling as I type this.
This was my first time trying out my new used Corona mill (Value Village ftw!) and I thought I'd start small. Plus, short boil/cool-down time means I can do a lot of this in my kitchen while helping to keep an eye on my kids, rather than staying up 'til 11pm doing a full batch. (That's hard when the kids are up at 6am...)
If I've got my volume estimated right, I got about 75% efficiency, which is pretty darn good for the first time with the Corona mill. As for the recipe...well, I was actually aiming for a soured stout, but I don't think I've hit it. The sour mash didn't smell so sour to me, and the wort looks closer to a medium-dark brown rather than black. But hey! Beer!