I love the idea, but I'm always worried a fully stocked Hosts file might break something. With a normal adblock add-on, if I load up a page and it looks wonky, I can disable it for that site and reload, to see if that fixes things. It's a lot more labor intensive to attempt that sort of bugchecking with a Hosts file.
It’s curious to me that, now malware and Microsoft actively and routinely defeat IP address blocking via the hosts file, we see it blithely promoted as here. On defective-by-design Windows systems , I’ll go right on using Spybot’s immunization, but effective IP address blocking belongs higher up, like say at the router.