Usually, threads like this, the OP has already made a decision and is seeking the council of others to validate it.
I say go for it. It's what you want.
I have the original Droid. I like the 4, don't care much about a larger screen, like iOS 5, and am intrigued by Siri.
I'm doing it. You're not THAT far ahead of me, sounds like it'd be a substantial upgrade for you as well.