Efficiency numbers reported by others are meaningless to me. Same for the fish stories. The reported numbers may be valid, but the information is of extremely limited value to me as a home brewer and fisherman. My efficiency is usually fairly low and I'm not at all ashamed of it. My beer, however, is usually pretty good. No one ever asks about my efficiency when they drink the beer. IMO, there are two main things that influence the efficiency numbers in a big way. The fineness of the crush and the OG of the wort. There are some other variables, of course, but those are the biggies. The system design is important, but for the same system the crush and the gravity rule. You can crush finer and finer until you are scared and beyond. You will eventually hit the wall and have a stuck mash, a partially stuck mash or sometimes an intermittently stuck mash. Any of those can be a lot of fun. The gravity factor is trickier. I can get into the 80's for a low gravity beers, but sometimes drop down into the 60's for very high gravity brews. Took me awhile to get dialed in to the variations due to the wort gravity. IOW, my efficiency from batch to batch can be very different depending on what I am brewing. There are too many variables with different systems, different degrees of crush and different beer styles for the reported efficiency numbers to be of any value to me.