For my part, Modules are time savers. DMing takes a lot of prep work (although less so these days if you have a laptop with a nice generator program) so anything that allows you to front load that better is fair game in my book. Having said that, modules aren't a substitute for real thought. Don't drop a bunch of dragon PCs into a dragonslaying module unless youre prepared to shoot the rails with a mass driver. (bonus pun: another name for a mass driver is a railgun).