I just did another partial mash with this method. Conclusion: grain bag used has a large effect on efficiency. I had to get a new bag before my dog destroyed my original grain sock (no, I'm not kidding). In the old bag, grains were free to move around a large portion of the stockpot, and I...
You could steep and sparge for longer. I usually steep for an hour, and sparge for 30 minutes. I imagine it'd be very difficult to get enough grain inside a bag and inside a pot to do all grain. You must also consider the lower efficiency with extracting from a bag. For the inexpensive cost of a...
I just tried this method on this recipe:
http://hopville.com/recipe/109638/home-brew/002---better-be-chocolate-malts
My gravity, and therefore efficiency, was a bit lower than I'd hoped but it seemed to work well. Thanks for posting the instructions and photos!