I actually worked the 11 pm launch for my store. After it was over, I took my copy home and immediately starting playing it. I've since sunk about 12 hours into it and am only missing a few characters to unlock. I'm about as addicted to this game as I thought I would be, it's just so damn amazing. I didn't really play Smash 4 too much so I'm not even recognizing a lot of the shared assets, it feels like a completely new game to me. It feels a lot punchier and well polished, like they fixed just about everything that everybody wanted fixed in previous Smash titles.
So far I have been really enjoying using Ganondorf, Simon, Ike, Ryu/Ken, Ridley, Bowser, King K Rool, and Snake. I've been messing around with other characters too as I figure out who I want to mainly focus on. REALLY looking forward to unlocking Mewtwo. I'm taking a small break atm but I'm about to hop right back in. I feel like a kid again with a new smash game unlocking 60+ characters. It's a great time to be alive.