What a goofy looking set. I have a number of the D&L caverns sets from their KS, and all of them are significantly better looking than this one, which is basically a repaint of some cavern pieces along with a few new additions. I suppose to make it look more Drow? To me, this set is barely 3d terrain, given how few walls are included.
As far as Underdark caverns go, by FAR the best option is Dwarven Forge caverns, either painted yourself or in their "Underdoom" paint scheme (NOT "Underdark" tm). But, you know, $$$$. Wizkids also puts out a (sort of) Caverns set in their Warlock Tiles line (kind of), but it is widely panned and the less said the better. It's really more like desert scatter terrain.
Anyway, the pros of D&L terrain are that it is significantly cheaper than DF for the amount of table coverage that you get, and their "prismacast" automated painting system
can produce good results, even if they woefully missed the mark on this set. The cons are that it relies on a connector system that is even worse than the Warlock Tiles one, if you can believe it, and all the pieces come on sprues, so significant assembly is required. And some paint touch-ups, IMO, and then magnetizing the tiles and shortening the wall clips if you want them to be fun and easy to use. But if you put the work in (I did), then they are a good option, in my case, for offering some settings that aren't covered by DF.
Here are a few images of their other sets, along with a few shots of how to magnetize them and fix the wall clips: