I agree with everything said...
But having said that, I bought my ITs on a pre-wired guard. Nice high quality work, BKP even wired it non-standard for me when I asked (master tone covering all three), at no extra cost - I wasn't expecting that, I'm guessing it meant they did it especially for me :D
The advantage for me is that I now own (for two strats) three sets of pups, each on their own pick guard with controls. If I want to swap, it's a lot quicker and involves three solder joints (two for the jack-socket, and one for the ground on the tremolo claw at the back).