Getting a hair system

[BoSox]

Finally made the decision to get a unit. No hair transplant will give me the look I want.

My question for you experts is, how come some people have their hairs super short on the sides, and some have to grow it long to blend a system? My hair is fine, and sticks out, so I have to grow it longer on sides so it sits down, and blends in. I wish I could trim it shorter on sides, for I like the clean shorter look.

Also, why aren't we seeing more full cap units? Are they not effective?

Thanks!