I'm level 42 in A3 and so far it's been pretty boring. My right hand is holding my head while my left mouse button is soloing most of everything, with my right button smashing the heads in of bosses whenever they arise. I've gotten so much sets and legendary items that I kinda feel disappointed now when they don't drop in the next 10 minutes. Green and Blue items are about as interesting as white ones in D3. My engineer looks nothing like an engineer apart from his permahump and right now, in fact, looks like a colorful Lego character. My two stashes are full and there is nowhere left to put stuff in. At the beginning I gained so many levels in the first 30 minutes that I just let the skill points stack up before I began choosing skills, because I figured otherwise I'd have to pause my gameplay every 2 minutes or so. All the NPCs sound like broken robots and the story is so far away from my mind that it feels like I'm just playing a tabletop game made entirely of white blocks. There have so far been about 6 varieties of fish over the ten or so Promising and 4 Secret Pools I've found. The only actual puzzle was in A1 and I solved it in about 3 minutes, since then I've had a "follow the light" and, er, perhaps 1 more that I can't really remember. The minimap shows too little terrain, but the maps on the right/center/left end up taking so much space I can't see the screen. You can get full item sets by just porting out and inside the town since vendors sell them sets and reset each time you leave.
So far my chihuahua is the best thing in the game yet.