Well it is called a "host" isn't it? lol.
Seriously, it isn't an exact parallel. The bread becomes Christ's body, it doesn't just contain Christ's body. We do not "become" Christ just because He is within us.
I don't see the difference.
Well. There are actually more similarities between beliefs than I suspect any of us are willing to admit. And there is some overlap of concepts that I suspect cannot be put properly into human language. We are incorporated into Christ, we are a part/member of His body. And this is true in a "real" sense. But that doen't mean that we are a "piece" of Christ. Christ is within the believer, but He is certainly not limited to that one location, nor is He reduced in substance when a new believer receives Him for the first time, nor does He "expand" to fit the new larger "body".
It is both "true" that you become a part of Christ and "true" that you remain yourself. Understanding this unity and distinction is probably on the same level as the presence of Christ in the host.
I'll ask you the same question I asked Dave: Assuming that Christ literally meant that the bread was his flesh and the wine was his blood, then how do you justify biblically that any bread or wine besides the pieces he actually held at the time can do the same?