It is a very enjoyable game for a theory crafter, and anyone who enjoys the D2 style of crawl.
Some things to keep in mind when playing for the first time.
Don't worry about your first character being perfect, use it to test out a 'build' you may enjoy.
Keep in mind that crafting items in that game are the currency, there is no gold drop, like there is in many others of that genre.
If you get serious enough about it, use some of the free skill tree builders out there so as not to get too overwhelmed by the massive amount of choice presented.
It is a pretty decent game all told. I enjoy it in spurts, usually around when they push out new seasons, though Diablo 3 holds more of my attention. Out of the many builds I enjoy, I think the weapon (your choice) and shield currently, is the most beginner friendly. Really good damage and you don't have to concentrate of much besides staying alive and attacking.