I am playing on hard difficulty and am currently enjoying the game way more than I did when I was playing in normal mode. The game is at least hard enough that I die more often and I love that. Before I was not dying at all and was boring me to tears.
I decided to try different classes and am currently enjoying playing the Demon Hunter. I was playing the monk but somehow it got a bit tiresome the Demon Hunter forces me to kite and play with more thought then merely smashing keys as the monk and also the resource management on the Demon Hunter is tougher.
My question since I am only playing on Hard mode and then I doubt very much I will try other difficulties will I get any benefit from buying Reaper of Souls. I don't like the Crusader and doubt I will play that but I am interested in the bounties and rifts. With the gear I get from hard will I be able to take advantage of the bounties and rifts or are those only for harder modes than "hard".
Comments
I think rifts represent the majority of gameplay today. All of the end-game content is about rifts and bounties, to the point where I wouldn't even consider running the Story mode again.
The difficulty is adjustable based on your preference, though I believe Torment 1 is seen as the "baseline" for accessing all of the gear.
If you mainly enjoy the Story Mode and dislike clearing random zones, then I'd say you might not enjoy Reaper of Souls. With that in mind, all of the post release content revolves around running random content (it is pretty much the main design pillar, story being secondary). If I was selling Diablo 3 to a completely new player, I'd highlight that it's a game about running randomised maps and collecting better loot with each run. I'd also say the expansion is mandatory, as you can't do any of that without it. If you bought it for the story though, then I assume you can play through the story without the need for an expansion (it won't really enhance the story aspect in any significant way).
Titan Quest is also worth a play, if you haven't tried that already.