It's a matter of choice, as with most things. I myself am *not* a very technical person and I have no idea how a soldering iron works. As such I'll have to spend $50-75 for the local shop to install them, plus the cost of the pups. With the prices I'm faced with in holland it's just more practical to get a guitar I like as it is. Aside from that it is, for me, a tough guess to estimate how my guitar would sound with different pups as that takes time and experience. So for me, in my position, changing pups is not a good idea.
And then again, if you know a lot about pups, how they interact sonically to different kinds of woods, if you can install them yourself or know someone who will do it for little money, if you care for having a 'personalized' guitar, or whatever reason I forget, then it might make perfect sense.
*Mental note: be a little more open-minded...* ;)
