Yes, pattern is important, but so is color and the dyes used in most cammies are not the best color.

The USGI pattern is great but suffers from incorrect color.  Sometimes a particular lot is colored correctly -- the tan is bright, the black is dark.  The green -- officially known as light green -- should be bright, too and the brown (actually called "loam") should be a reddish brown, almost like clay.  You see, the USGI pattern actually deceives the eye by having the green and loam at the same "greyscale" value -- if you were to take a black and white photo, the green and brown should be one tint of grey and you would not be able to distinguish between the two.

Some of the foreign cammies have that bright green and reddish brown pattern.  For all-around use, that's the colors you want.