YMMV :-)

It did :)

If you add a hits counter as in my benchmark above, you'll see the reason why. Buk2 does not match anything at all (and fails slowly) in your benchmark:

c:\test>junk6-b
          Rate    orig    Buk1   JOOST    Buk2 jwkrahn
orig    1.59/s      --    -30%    -55%    -59%    -63%
Buk1    2.29/s     44%      --    -36%    -41%    -47%
JOOST   3.57/s    125%     56%      --     -8%    -18%
Buk2    3.88/s    144%     70%      9%      --    -11%
jwkrahn 4.35/s    173%     90%     22%     12%      --
{ Buk1 => 203, Buk2 => 0, JOOST => 203, jwkrahn => 203, orig => 203 }
...............*********
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And that intrigued me, until I noticed that you are not chomping your data. Once you chomp it, you'll find that Buk2 matches the same number as the others, and runs much (1100%) faster than grep:

c:\test>junk6-b
          Rate    orig    Buk1   JOOST jwkrahn    Buk2
orig    1.59/s      --    -29%    -59%    -64%    -97%
Buk1    2.23/s     40%      --    -42%    -49%    -96%
JOOST   3.84/s    141%     72%      --    -12%    -93%
jwkrahn 4.37/s    175%     96%     14%      --    -92%
Buk2    53.0/s   3231%   2280%   1281%   1113%      --
{ Buk1 => 203, Buk2 => 203, JOOST => 203, jwkrahn => 203, orig => 203 
+}
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Alternatively, just add /s to the regex in Buk2 in your benchmark, and it will also allow Buk2 to work, but it will only be 500% faster.

c:\test>junk6-b
          Rate    orig    Buk1   JOOST jwkrahn    Buk2
orig    1.59/s      --    -30%    -55%    -63%    -94%
Buk1    2.27/s     43%      --    -36%    -48%    -92%
JOOST   3.54/s    122%     56%      --    -18%    -88%
jwkrahn 4.33/s    172%     91%     22%      --    -85%
Buk2    28.5/s   1693%   1155%    707%    559%      --
{ Buk1 => 203, Buk2 => 203, JOOST => 203, jwkrahn => 203, orig => 203 
+}
[download]