I'm living with one right now, it's not horrible but I grew up with six older sisters so I'm used to this:
I will say that it was a little weird at first when we were getting to know each other, but after the first month we found our comfort zones and it was cool from then on. Is she attractive? She's not my type, but she dates plenty of respectable men so she's not "ugly". I will say that if she and I were attracted to each other it would be hard to keep things civil.
If you find yourself at all attracted to a girl while looking at the place I would say don't do it. Booze can be a powerful catalyst for rash decisions that you both will regret later. Think of it like this:
-You met a girl and after one date decided to get and apartment together.
-You realize a month later that you haaaaaate each other, and soon break up.
-Now you're stuck in a lease together.
Does that sound fun? If not, then be careful about moving in with a girl you may become attracted to; not that you're guaranteed to know that up front, but if right off that bat you look at her and think "She's kinda cute" then you're not ready for a female roommate.
Now, if you two seem like you'd be "whatever' about each other -- and she isn't a slob/teh crazies -- then a girl roommate is no better or worse than a male roommate. You miss out on having some bro-rrific fun, but you can go out and play wingman for each other.
Also (SPOILER ALERT!!!) girls do not walk around in their underwear in their apartment. While at home, a girl will wear:
1. A baggy t-shirt that they've had since high school
2. Their hair in a bun, or they simply let it go to hell.
3. Stained sweat pants that makes their ass look as appealing as a plate of soggy waffles.
4. Socks that look like they were fashioned from the cloth off an old Muppet toy.