Ok, so for those of us that played Diablo III on Xbox 360 and PS3, if we purchase the "Ultimate Evil Edition", what are we getting besides the new chapter and Crusader class?
1) Will there be new legendaries in "Ultimate Evil Edition?"
2) Will there be new skills & talents for the vanilla D3 classes?
3) What changed or was added in the PC version since the last console D3?
Think of your question like this.
"What will I miss out on if I play Diablo 2 without Lord of Destruction?"
Just as Diablo 2's expansion greatly "expanded" upon the "Diablo 2 experience" by adding new monsters, a new act, new classes, new ways to craft items.
Diablo 3's Reaper of Souls expansion is similar in this regard by greatly improving over the base Diablo 3 experience.
If you want to get the "definitive" experience out of the Diablo III. Then the expansion is worthwhile in that regard.
The higher level caps, higher artisan / crafting levels, new legendaries, The Mystic and Transmogrification, adventure mode are changes that you won't ever experience in standard Diablo 3.
Reaper of Souls is MORE then just an extra class and new act.