I lived in Xalapa for a couple of years and went there thinking it would be a cool option one afternoon. All I can say is don't waste your time. Head to the Museum of Anthropology instead and you will be blown away by their collection of Olmec artifacts!
Overrated ... there are better equivalents in other cities! We went to a similar Museum in San Luis Potosí which was far better with more interesting interactive exhibits and it appears to be a bit dated (also the Papalote in Mexico City seems better as well).
This place needs a serious makeover quickly. Not worth it unless you have time...