I've done it, and really enjoyed it!
Like jimbob says, it is not a walk of unadulterated beauty and should never be undertaken with that in mind. It deliberately seeks out habitation as, in the old days, that meant safety for travellers. Consequently, especially round larger towns and cities, it can be ugly, with industrial estates, motorways, suburbs and airports all needing to be negotiated. However, the upshot of that is some wonderfully historic city centres such as Burgos and Leon encountered on the way.
It is a lot of walking on roads and hard tracks too, and this will deter or disappoint many as well. I just think it is best to be aware that it is not a wilderness walk no matter what any portrayal may have you believe. And it will be busy, too - it is probably the busiest footpath in the world.
Having said all that, it was a fantastic experience. We chose to use B&B and small hotels along the way, rather than the often grim hostals and alberges. As well as being a Pilgrimage it was also a holiday, and I'm not sure that forcing privations on ourselves would have appealed. But I also think that the best way to approach it is in your own way, whatever that is, because to my mind it is worth the effort of completing.
It didn't change our lives, and we didn't make friends for life en route either, but we met some great people and had a lot of fun, and it was still an experience I wouldn't change for the world - in fact, we are now in the process of walking the Le Puy Route - the feeder route from central France - and have plans for more after that, so I think I can safely say it had a considerable influence on our walking!