I just ran across an entertaining game played between Bergez and Hebden in the 2nd round of this year's Hastings tournament. Light comentary by Steve Giddins can be found at
http://www.hastingschess.org.uk/2009/commentary.htm 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.e5 d5 6.Bb5 Ne4 7.Nxd4 Bc5 8.Nxc6 Bxf2+
9.Ke2 Qd7 10.e6 fxe6 11.Nxa7 c6 12.Nxc8 cxb5 13.Nd2 Ra4 14.Nxe4 Rxe4+ 15.Kxf2 0–0+ 16.Kg3
16...Qxc8 17. Kh3 Qc4 18. g3 Rf2 19. Re1 Rd4 20. Qh5 Re4 21. Be3 Rf5 22. Qe8+ Rf8 23. Qe7 Qc8 24. c3 d4 25. cxd4 e5+ 26. Kg2 Qc2+ 27. Kh1 exd4 28. Bxd4 Rxe7 29. Rxe7 Qc6+ 30. Kg1 Rf7 31. Rxf7 Kxf7 32. a3 Qd5 33. Rf1+ Kg8 34. Bc3 g5 35. g4 Qd3 36. Re1 Qf3 37. Re5 Qxg4+ 38. Kh1 h6 39. Re1 Kf7 40. Re3 Qf4 41. Re1 Qf2 42. Rg1 Kg6 43. Rg2 Qf1+ 44. Rg1 Qf3+ 45. Rg2 h5 46. Bd2 Qd1+ 0-1
A similar line, with 9.Kf1 instead of 9.Ke2 played in the game above, known as the Kaidanz Variation is (was?) more commonly played. 9.Kf1 has also been discussed in detail by Nunn (see the game Corden-Nunn in the book
Secrets of Grandmaster Play) and was the subject of an excellent Hard Chess column (which can be found
here) written by Mark Morss (ChessPub's Markovich).
Of course the game's outcome, by itself, would not suggest that 9.Ke2 is an improvement over 9.Kf1. Maybe it's unclear, but Black seems to have very good compensation for the sacrificed piece in the diagrammed position. White might be able to improve on 11.Nxa7, however. Any opinions or relevant theory on whether the newer 9.Ke2 is superior to older 9.Kf1?
Later found some mention of 9.Ke2 in a thread from 4 years ago where Feb suggests 11.Bd3 is White's best and that the game line 11.Nxa7 c6 12.Nxc8 cxb5 13.Nd2 Ra4 favors Black.
http://www.chesspub.com/cgi-bin/yabb2/YaBB.pl?num=1091218196/9#9 . This move was given by feb on the N.J.Chess forum in 2004 (the link I have doesn't work anymore), with the example "17.Qd2 h5 18.h4 Qf6 -+".