I've been to similar ancient manuscript exhibits (dead-sea scrolls in Israel, Guttenberg Bible in Germany). All of them were a better experience than this one.
First, getting tickets is a frustrating experience. Electronic tickets appear to be REQUIRED, but he web sight doesn't say that. If you show up, you hopefully have a mobile device with Internet access and sufficient data (don't always assume this for visitors from another country). You have to use a credit card (no cash was accepted). People from outside the EU (or at least from the US) often get hit with a currency exchange fee (hence my preference for small amounts of cash). The whole ticket acquisition experience started the tour off poorly. Just explain an the web site that pre-purchased, electronic tickets are highly recommended (because if you show up, that's what you'll have to do anyhow)
The staff are friendly and helpful. The displays interesting and educational, yet the whole experience seems a little small for 18E/person. What percentage of the space is the display and what percentage is the gift shop?