Nice topic!
I'll be honest. Hair matters more than it should for me. DX Maybe because it's soft?
But it's definately not the most important thing, and different hair looks better on different people with different looks. I think that some women look better with short hair, even though I prefer really long hair.
With this in mind I'm not sure I'd go for either of them. Shaved heads are a dead turn off for me, I'm afraid. But a boring personality is ALSO a dead turn off, probably moreso. If I REALLY got along REALLY well with the first woman and she totally liked and understood me and we could totally relate to each other, I might persue her. If the first woman just had SHORT hair, though, then I'd definately go for her.
Then again, when it comes to hair, practically no girls that I see in real life are too sexy to me. I like long blood red hair combined with a gothic style, and the only women I've seen with that are like goth models and singers for industrial bands and what not. But most hot gothic women with blood red hair that I come across, I find to be extremely, extremely hot to the point where I can, in some cases, overlook some of the flaws of their personality. (Not if they're totally psycho and sadistic though.)