Learn Dutch: Het werk is een stuk beter, behalve dat het choquerend is. - The work is a lot better, except that it is shocking.

Behalve dat (except that) is a subordinating conjunction. This means it introduces a dependent clause, which pushes the conjugated verb (is) to the very end of the sentence. That is why it says het choquerend is rather than het is choquerend.

Why does een stuk mean "a lot" instead of "a piece"?

While een stuk literally means "a piece", it is frequently used as an adverb before comparative adjectives to mean "a lot" or "much". Therefore, een stuk beter translates to "a lot better". You will also commonly hear phrases like een stuk sneller (a lot faster) or een stuk duurder (a lot more expensive).

Could I use buiten dat instead of behalve dat in this sentence?

You could, but it would change the tone and meaning. Behalve dat means "except that", pointing out a clear flaw or exception to the work being better. Buiten dat means "besides the fact that" or "apart from that", which typically adds information or lists an additional detail rather than contrasting it.

Why is choquerend spelled with a "q"?