Compared to the crom coin ingame shop, the expansion is a steal even if not factoring the map in. Three armor sets, a really great building set, some other stuff.
The map… is nice, but weird, so it’s a matter of taste, I’d say. The Exiled Lands have a progression: desert, praerie, jungle, northern plains, snow, volcano.
The Isle of Siptah does not. It’s apparently set up more for endgame multiplayer gaming, including PvP: Resources are scattered across the map, so no one clan or player can monopolize a kind of resource.
It does have a story, but just as the map around it, it isn’t set up as a path leading through the map, but as hints scattered around in a large circle, without a clear beginning or end.
I, personally, like the map, for the way I use it: As an extension of the Exiled Lands, and island my character can travel to and back from.
I also played one or two games on the Isle of Siptah from start to finish. Works, too, but I miss parts of the Exiled Lands.
The map itself is quite nice. Some rather challenging outdoor regions especially in the south of the map. It’s a bit less lore-heavy, but more hack 'n slash. So, when you want to kill something without going to jail, this is a good place to do that.