Really good in my opinion. You will likely not win many legends in your first (or second) playthrough. Next, multiple legends have different end bosses and goals (like star shield). It has only 4 scenarios (excluding the black cog bonus legend) but it doesn't have a tutorial scenario like the Base game.
The mechanics are new and interesting. There is more combat involved while keeping the puzzly (is that even a word?) feel of the game. The narrative is excellent. Long story short, if you enjoyed legends of andor this is a must-buy.