Thats awesome!
On reddit a gamer posted that Wine-staging works good with Diablo 3, but I mostly had success with ProtonGE. I'm also playing co-op with my wife, we initially played through Act IV two times, but now we have Reaper of Souls which includes Act V... its pretty dang fun! We can not enable Adventure mode until we complete Act V, but I've heard really good things.

That is exactly what we are looking for! Can't wait to try Adventure mode...
Unfortunately our characters each have over 5 million coins, so no sure what to spend it on?

That is GREAT news! This is exactly why I purchased Reaper of Souls!
We love Diablo 3 and all of the features, amazing visuals and high-speed action...
The only two other games I've compared to Diablo 3 is Torchlight II and Grim Dawn. I eventually purchased all of the Grim Dawn expansions and they are amazing, but one thing that eventually become old is how the enemies attack. They basically hangout in an area totally static, then when your character is in range they attack like a swarm. Sometimes there are so many enemies swarming that it slows down the game. So I learned to creep in and wake-up a few enemies, take them out, then wake up some more. Which isn't as much fun.

Diablo on-the-other-hand is more dynamic... not much, but just enough to make it interesting. One thing I've missed in Action RPGs is more dynamic enemies. Enemies that travel in packs, or guard areas or roam around the level. This would be more interesting then just taking hour horde after horde. Gets kinda old. Games that achieve this are Borderlands, Skyrim, Assasin's Creed series, Deliverance. They all have living worlds where there are guards travelling from town to town and people living in towns or merchants in towns. Albion kinda achieves this, but its real MMO gamers roaming the world not NCPs. So it has a dynamic action to it as well.

Anyways, I'm looking forward to a lot more content, action, storyline and upgrading my character.