From the sounds of things, the pros outweigh the cons by quite a bit. Take a chance. You'll never forgive yourself if you end up stuck in the same place for another six years....and upward mobility is almost always a positive thing on the whole. If you get that experience and you don't like the job, you'll be qualified to apply somewhere else (maybe for more $?) Who knows. But life's short, so why not go for it.

And good luck!