Define great quality. I consider my Felt Brougham to be pretty great quality for what it is, but a lot of people wouldn't even take a second look at it.

You won't notice the difference between a 22lb steel bike and a 17lb aluminium bike. Unless you're doing hill climbs, and you shouldn't be doing that on a fixed gear.

I promise, you will notice the aerodynamics even less than the weight.

Light, comfortable, you can afford it.

Pick two.

See: Quality.