I prefer the File Sharing apps for getting MP3s myself, that much I don't dispute at all. But what we're talking about here is getting the BIG files (movies, episodes, etc...).
I'm on Cable Modem, and at least for me, IRC has been the more solid/reliable connection. CuteMX is up and down like a Yo-yo or it's just plain down. Napster I don't even bother with anymore cause I haven't been able to get on and Gnutella ain't exactly user friendly.
Plus I just CAN'T STAND to see all the BEGGING AND WHINING going on in the File Sharing neighborhoods... 'PLZZZZ WOULD SOMEONE SEND ME THIS' or 'PLZZZ MAKE ME AN OP'. And the ONLY reason people share files at all is because THEY HAVE to in order to get files (so you KNOW they're not gonna share the good stuff). File Sharing apps put you in the mentality of 'horde and trade'
At least on IRC, people set themselves up as FServers (SCREW those monkeys that advert their FTP to only force you to have to jump through hoops to get access). If you see something you want get in the queue and wait. No begging, no whining