How good are BRONZE Razors?

I just about all of the ancient Egyptian tomb paintings, the men are portrayed as clean-shaven. In addition, I undertand that most men 9and women) shaved their heads…this was because of the hot, humid conditions. How did they doe this (with bronze razors). I happen to have some bronze cutlery, and the fact is that bronze does not give a very sharp edge. So, was shaving a torture in Egypt? Or did they just pluck the hairs?
Incidentally, even with the iron age, razors must have been very dull-how did the Romans manage their shaves?

Some background:

http://inventors.about.com/gi/dynamic/offsite.htm?site=http://www.quikshave.com/timeline.htm

Some excerpts:

Prehistoric - flint.
3000 BC - copper.
1500 BC Scandanavian - bronze.
Romans - iron.

Alexander the Great was a shaving freak.