Hi sheeeng,
An interesting article. One I would recommend serious VBA-ers to read, but ...
FWIW, my take on this is that one deliberately sacrifices performance for other gains when using a language such as VBA. If performance really matters I would use another language (although it might be cheaper to buy a faster chip and stick with VBA).
Some of the tricks in the article seem to sacrifice readability and maintainability in particular - if you are comfortable with the code and no-one else is going to have to work on it then fine, but in a corporate environment the overhead of someone unfamiliar with some of the techniques having to understand the code is quite possibly more expensive than the performance saving.
A couple of (to me) interesting points:
I can see that changing "" to vbNullString might give some benefit, but cutting execution time by half. WOW !
vbNewLine faster than vbCr? I would have expected the opposite as vbNewLine has more processing to do - the article doesn't say so but one should always use vNewLine anyway as it's platform-independent.