Just my two cents: after several years and projects, CI applications have always turned out to be quickly and easily maintainable. You also end up developing your own coding style - CI helps a lot with that, instead of getting in our way. If you've ever got stuck into a legacy, keep-it-alive-forever zend conundrum, you know very well what it means
So, I think I owe a lot to the guys at British Columbia (having happily survived the big panic of EllisLab dropping it all at some point)!