http://www.killermovies.com/forums/showthread.php?threadid=382350&pagenumber=4285#post16576658
Femtoseconds and attoseconds.
Goku simply doesn't operate on this level of speed.
^^^ NewGuy gets it.
Speed is the big elephant in the room, because Dragon Ball characters are known for being injured by weak hits if they're caught off guard.
Kind of hard not to get caught off guard if the other guy is operating on high enough level of speed relative to the rest of the world, that they may as well have full on time stop powers.
Of course, the smarter backers of Dragon Ball argue from power leveling, which looks good on paper but kind of falls apart when Dragon Ball hasn't used conventional power leveling in Super, nor even pretended to define what each level actually does in canon (Outside of source books, which mean jack all..)