Easy to navigate. And truly FREE! We left a donation anyway. If you've been to "The Met" in NYC, then you know that there is a "suggested donation" that certain people will try to make you feel terrible about if you don't pay the recommended amount. I have friends on a very limited budget who have been made to feel terrible when entering the Met. Not here.
This museum seems too proud to beg. We literally walked in, passed very polite security guards, picked up a map (2 euro donation) and found the Rosetta Stone in 5 minutes.
Best thing about the map that makes it worth the price is a list of popular items in the museum on a course that takes you through the museum in about an hour. We spent about 1.5 hours before leaving to catch train to Bath. Will go again if in London.