Incredible atmosphere, poor balance.

If you asked me to point at an iconic minecraft mod,
this would be one of my picks right alongside TMI, Create, & HBM's.

The dimension designs are atmospheric and extremely fun to explore.
Every dimension has a theme,
some being explicitly connected in the physical sense-
which is the one part where the mod falters in my opinion.
Once the rooms become predictable, the mod loses it's appeal.
After only a couple excursions in my first proper play-through with the mod,
I immediately started recognizing the same trap rooms with free diamond blocks ,
and a chain of rooms that results in ridiculous amounts of items,
especially with other mods that mix themselves into the vanilla loot-tables.

But despite that, the first experience is really worth experiencing.
If you know someone who hasn't played this mod yet,
throw them in head first, that's my recommendation.

And as a side-note,
i really like the personal dimensions, they create a very unique safe-space to base in.