When I first got a 9-speed cassette I was moving up from a 7-speed system. I gave it some though and then decided that I liked the idea of keeping a closely space 7-speed setup and keep the other two cogs bigger to use as bailout gears. Thus, on that bike I'd ride it as if is was a 7-speed cassette most times but I had the option of using two much lower gears when hitting bigger hills or hills with headwinds.

I kind of liked the 50-34 crankset but that was partly because of the drilled rings. That crankset is in my wall ornaments box now.

the really nice thing with cassettes is that you can make up your own to match YOUR requirements.

Cheers