I think the short answer is no; however, you will get a better-sounding system if you spend $450 on a stereo receiver. I have an HK 3470 and it's great. ~$500 surround receivers are mostly preamp circuitry with some low-powered amps added on. My upgrade path is to eventually get a receiver with preouts so I can use my 3470 as an amp for the front channels.

Stereo is great for me because I listen to a lot more music than movies. How many movies do you watch on DVD that actually have 5.1 sound? And of those movies, how important is the surround to the movie? Would you rather have a great stereo system or a middle-of-the-road surround sound system?

-Cooper