Although now that I have a love for the American version, do you think that it will make it harder for me to like the British version?
No doubt it will. They're really just two different flavors. After being used to the British version, it feels like the American version is beating me over the head with the jokes, and the character development feels cheaper and not like the primary focus. On the other hand, if you're used to the American version, you might feel like the British version is too slow and boring.
I do love the cast of the US version, at least as far as Steve Carell, John Krasinski, and Jenna Fischer.
Oh, and PeterChenoweth, I can understand not getting into the British version after one episode. It took me a few to get into it, and by the end of the series it was cemented as one of my favorite shows of all-time.
I've watched a fair amount of the US version. I'm sure at some point I'll make a point of watching every episode.