The difference between looking ahead and not looking ahead is a pretty huge difference. When you look ahead during a solve, you can practically feel that adrenaline rush and you will somehow KNOW that you are going to get a great time.
With NO look ahead:
6: 00:16.57 x
5: 00:17.23 x
4: 00:16.43 x
3: 00:16.17 x
2: 00:18.26 x
1: 00:16.40 x
Mean of 6: 16.84
--------------------
WITH look ahead:
12: 00:16.28 x
11: 00:13.83 x
10: 00:13.12 x
9: 00:14.65 x
8: 00:13.70 x
7: 00:16.89 x
Mean of 6: 14.75
(No look ahead) - (with look ahead) = 2.09 seconds
So my lookahead saves me 2 seconds on my average.
If you assume that I would pause in 4 places more than usual by not looking ahead (before executing each of the corner edge pairs) then I pause for 2.09/4 = 0.52 second per pair to find the pieces and identify what to do to solve it. So F2L pauses for me average 0.52 second each I guess you could say.
