Guys always worry about their height way to much. I have personally dated guys all over the scale (not a whore, I promise). I'm relatively tall for a girl, kinda. being 5'6'' there are some guys still shorter but, a lot taller. my current boyfriend is 6'2'' and I don't like it as much as guys who are 5'8''. it all depends on the girl your dealing with. I personally don't mind whether your "average" tall or short. You just need to treat a girl with respect, and love. She shouldn't care anyways. not a big deal.
I don't really have a strong height preference... I guess a few inches taller than me would be most convenient, so yeah, 5'8" is good. Before my current boyfriend, I had a crush on a guy who was exactly my height.
I typically do like shorter guys over taller, because I don't like a guy to be so much taller than me that he has to bend way down and I have to stretch my neck and stand on my tip-toes to kiss him. lol. I'm 5'4" and my current boyfriend is about 5'6" or 5'7", and I like it. don't worry, it's not a huge factor for most girls, unless maybe if they are like really tall girls. otherwise, you're a good height.
I don't really care how tall someone is. It's not even a huge factor.