my efficiency went up a bit when i got my 3 roller monster mill.
gotta have a big drill to run it. the battery on my 14v cordless drill died in about 90 seconds the first time i tried to run it...
with the gap at .38 or .40" i was getting about 72% efficiency, the crush looked like this.
http://farm4.static.flickr.com/3448/4605330054_f298edfaa5_o.jpg
i moved the gap down to .36" and now i'm right around 80% efficiency. i have no desire to try to get my efficiency any higher.
the mill was shipped fast and easy to assemble. works fine. i'm sure it will last a very long time.
80% is just fine IMO. I'm always very skeptical when I read reports of very high efficiency and I don't chase it myself. I'm happy to know what to expect and I deal with it. I'm an inefficient brewer in more ways than one.