I guess one way to show which driver has been faster through 6 races is to check which of the two, Kimi or Fernando, had the faster lap in each race (A better way is to average all the laps, but I'm not investing the time for that).
And the survey says...
In Australia: Kimi had the 10 Fastest Race Lap at 1:33.691. Alonso had the 3rd fastest, with a lap of 1:32.616.
Malaysia: Kimi had the 7th Fastest Race Lap at 1:45.129 Fernando was once again 3rd fastest, overall, with a lap of 1:44.165.
Bahrain: Kimi was 8th fastest, overall with an FL of 1:39.438. Alonso had the 12th Fastest Race Lap at 1:39.732
China: Kimi was 8th fastest again, with a best lap time of 1:42.300. Alonso had the 4th quickest lap of the day with a 1:42.081.
Spain: Kimi had the 11th Fastest Race Lap at 1:30.580. Fernando was 4th quickest on the day, again, with a 1:29.898.
Monaco: Kimi had the Fastest Race Lap with a 1:18.479. Alonso finished with a 5th fastest lap with a 1:19.727.
The Fastest Race Laps are bolded for the quicker driver. Simple math shows Alonso is ahead 4-2, so far, for anyone trying to use the fastest Ferrari driver of 2014 stat as a measure. I concede that "average lap time" would be better (Minusing out any collision/tech failure laps), but since Alonso has finished ahead in the first 6 races, I'm guessing he'd likely come out ahead in that stat as well.