New lands are, as such, a welcome sight to me. I like exploring: What’s behind the next mountain range?
Experienced CE players will know how the system works and will be able to game it to a certain degree. But if even some resources are not where you expect, that adds a lot of challenge to conquering a new map. For example, I searched my ass for Brimstone on one map, which seriously hindered all crafting efforts.
Always nice are “new” enemies, which does include just using the Siptah Surge Mobs such as Aquilonian army or Amazons - just stuff that isn’t really used so far.
Personally, I don’t like maps that look to artificial or unrealistic. Different biomes are much too close in the Exiled Lands for a non-fantasy, non-Giant-King-terraformed reality. But they’re still somewhat consistent: There is, for example, a mountain range between the jungle and the north which could at least to some degree explain differences in climate.
Islands should be exact squares. Rivers should have bents and some ocean they connect to. There should be some free space between settlements, ruins and other landmarks: People may settle in a ruined city, or in some distance, but not right next door to a lost city filled with undead, for example.
In a new map, biomes should also be somewhot logically placed, e. g. no snow biome just next to a jungle. That’s well done in most maps, but there’s a range of degrees in believability among them.
Too much darkness puts me off. Don’t know if that’s due to a personal phenomenon, but some maps or dungeons are very hard to play for me because they’re so god-damn dark, even with a torch in hand.
A play of light and darkness can be very atmospheric, but there’s more to that than just blinding the player with a blanket of shadow.
Several maps are a tiny bit derivative, i. e. re-imaginings of the Exiled Land. That’s fine and be fun to play, such as Savage Wilds has shown. But if one invests the time to create a new map, I think one could also try to not re-create the Exiled Lands, but invent a new story or tranlsate one from the many sources in Conan Lore into a video game map.