Unfortunately, for some of us, it was the only option due to the shortage at release. I'd rather have paid a bit more buying the HDD seperately than not having a 360 at all.
Also - I'm not a fan of Halo at all, however my brother got Halo 2 again so I'm playing it through out of summer boredom. It seems really glitchy, moreso than I remember, kinda sucks that. I think it's because of the 360. I don't see any graphical improvement, either.