So, I posted a little bit about Diablo III when it first came out, way back when. I enjoyed it for the most part, with my only real issues being in the storytelling department. Unfortunately, at that time I had not played through the game all the way to level 60, I only got to somewhere in the mid-30s. So because of that, I hadn't experienced any of the endgame, which is often the meat and potatoes of this genre. The endgame content of these types of games is basically just doing runs over and over until you find loot upgrades that allow you to do those runs more efficiently. Repeat until you get bored of it. The issues that people had with Diablo III's endgame basically boiled down to the itemisation. The loot just wasn't very interesting, and it took too long to find meaningful upgrades.
This was an almost direct result of the existence of the game's auction house. Whether it be by using in-game gold or real money, players could buy and sell items that they had found in-game. Because of this, finding decent items was a rare occurrence, otherwise virtually everyone could stick their loot on the auction house and make some money. It also meant that the most efficient way to upgrade your character was not by playing the game, but by simply buying upgrades on the auction house.
Since Diablo III's release two years ago, there have been a number of updates to help fix this issue, with the two main ones being "loot 2.0" and the now complete removal of the auction houses from the game. Loot 2.0, which overhauls the loot system to a more quality-over-quantity experience means you are now more likely to find more meaningful upgrades more often. Where previously a stat on an item could've rolled from anywhere between 1-100, it's now more like 75-100. Add to that much better legendary item drop rates (you're now pretty much guaranteed a legendary at least every hour or two, compared to my 3 legendaries in about 100 hours previously) means that the loot progression is much more satisfying and feels like much less of a grind.
This week also brought about the game's first major content update, in the form of Reaper of Souls. As well as adding a whole new act onto the story, the expansion also brings about a whole host of other cool new features. The biggest of these, Adventure Mode, essentially completely changes the way in which you play the game. Unlocked for all your characters once you've played through Act V once, Adventure Mode opens up the entire game and allows you to travel wherever you want, completing bounties. These bounties are usually quick, five minute affairs, where you travel to a specific location and kill a specified enemy, or complete a specific event. Completing these nets you experience and gold awards, as well as bonuses if you finish five bounties in one act.
But that's not even the coolest part. By completing these bounties, you will occasionally be rewarded with Rift Key Fragments. Spending five of these allows you go back to town and open a Nephalem Rift. These are essentially completely random dungeons (seriously, take every tileset and enemy type in the game, and throw them into an RNG) with a powerful boss at the end for you to kill. The monster density in these rifts also tends to be quite high, so the potential for big XP and loot gains is high.
The expansion also increases the level cap by 10, up to a max of 70. Higher level means better loot. Even some of the basic level 70 gears makes the best level 60 gear look terrible. Each class also has a brand new ability and set of runes to go with it, which first unlocks when you hit 61. The only one I've tried, the Wizard's Black Hole, is cool and seems to work well as a decent crowd control ability. There's also the brand new class, the Crusader. I haven't messed too much with it (only level 30 or so) but the class seems to play fairly similar to the Barbarian, with the main difference being a lot of more defensive abilities, which require resource spending to use, rather than being cooldown based. They definitely seem like they have the ability to be super tanky. Oh, and one of their passives allows them to weird a two-handed weapon and a shield at the same time. So that's pretty rad.
There's also a third artisan to go alongside the blacksmith and jeweller: the enchantress. She can let you enchant items, essentially completely re-rolling a stat on an item in the hopes for a better one, for a price of course. So if you find an item that is great all-round except for one bum stat, it's very much possible to fix that. She can also "transmogrify" items, altering their appearance. So if you find a really good upgrade, but think it looks ugly as shit, you can pay her to just make it look like another item of the same type. For someone like me who cares a lot about cosmetic customisation in games, this is a very welcome addition.
As for the actual new act, it's pretty good. I've only played through it once, but it felt to be of decent length. At least, much longer than the mostly disappointing act IV. Most of the new enemy types aren't particularly interesting, in my opinion, however, the new environment designs are probably among the best in the entire game. Strong art design has always been one of Blizzard's strengths and it definition shows here.
If you care at all about Diablo III, the expansion is definitely a worthy addition and worth picking up. If you haven't played the game much since release, you should probably give it another go. Even before the expansion there have been a number of improvements that have made the game vastly more enjoyable and rewarding to play. You don't need to upgrade to the expansion to experience the benefits of the new loot system. This is the Diablo III that should've been there at launch.