Au58 should have nice luster, but a very small amount of wear. MS60 will not have much (if any) luster, and also no wear. For many people Au58 is better than MS60, or 61 because of the lack of nice luster and also many bag marks. At least that is my understanding. You may want to check here, as I am no expert: http://www.cointalk.com/t115123/
Yeah, a true au58 is a much better coin. Btw, 60 is not really used any more, and most real 58s are being slabbed as 62s as "cabinet friction".
The AU-58 will be a beautiful coin with very slight wear and the MS-60 will be butt ugly with no wear.
The easiest thing to keep in mind is that an MS60 should have significant issues with eye appeal, but no wear; whereas an AU58 should have the slightest wear, but otherwise might be quite attractive.
