I completed my first AG this past Sunday, and I opted for the double batch sparge. Having said that, it was a smaller grain bill (8.0 lbs). However, I overshot my preboil SG and my OG by 1.001. I couldn't complain, FWIW my brewhouse efficiency came out to ~81% (80.78% to be exact).
I say Sparge, better yet I say sparge twice with two equal volumes, Kaiser here on HBT has an article on batch sparging, if I read his info right it will increase your efficiency by about 2%, then it gets techincal about wort quality, but I think that is negligeable.