The church itself is fascinating. I would skip the audio guide unless you are especially interested in Dominican history as each stop along the way includes a 5 minute presentation. Also we had trouble with the functionality of the iPads and they had to replace each of them more than once.

Santa Maria Novella is admirable. The audio-guide would benefit from being more ambitious from an art historical point of view. The commentary on Masaccio's Trinity, for example, does not put into sufficient perspective (it is the case to say so...) the milestone that this work represents in the history of Italian Renaissance art and focuses to secondary aspects that are quickly forgotten. In any case, go visit Santa Maria. Do not miss !

It is far, far easier to just pay for a ticket at the entrance, instead of finding the place to trade the voucher for a ticket. It was confusing. I gave up trying to find the place, and just purchased another ticket at the entrance. It is a nominal amount, the cathedral is mostly empty, there are no lines at all. One less star for that. However: The museum is quite significant for both its architecture and art (Masaccio fresco!) and well worth the visit. Don't forget to ask about the camera obscura meridians, and to take a walk around in the courtyard/ loggia - there is more to see outside the cathedral. 5 stars for the cathedral itself. Minus one star for the confusing voucher exchange. The experience itself was well worth the modest amount of money I paid at the entrance. A guide might be helpful for some people, to hit the highlights.