I say you should try it at least once. I ride on roads with no shoulders with 45+ mph traffic regularly. But I pretty much ALWAYS take the lane. There's so much trash up against the curb anyway and fixing flats is hard and annoying, so I like to ride just to the right of center (this is legal in Texas as the law does not clearly define a zone for cyclists to be in, just as far to the right as is "safe", which in my interpretation is just right of center and a few feet from the curb - but I would check your state laws).

I used to get really nervous but after a while you realize the vast majority of cars are trying not to hit you. And after all, most drivers need a lesson in patience anyway