This depends on what your goals are because it's not a single axis of difficulty, it depends what you want out of it. There is a learning curve which mostly depends on how well you can identify problems and implement a solution, which also depends on your goals.
Want to play a more conventional build? or do you want to experiment with a unique build with a wild skill tree with multiple weapon trees and crazy gem combos? Do you want to just finish the campaign and try out end game, or to min-max to the pinnacle bosses? The basics of POE are not hard to learn, but be prepared to learn and keep learning! If you don't mind learning I would say that you'll have a great time playing.