Ok so my experience goes like this:
Got to my store in deptford nj 2 hours early at about 2 o clock for this thing to start at 4 and when I get there there was already a good 40-50 people in line (it was almost wrapping around the building at this point!).
at about 2:45 an employee came out and said he had good and bad news, the bad news was that you wouldn't get the coin today, but rather when you pick up your pre order. The good news was that
everyone in the line would get a coin (granted the line was still relatively small at this point).
Fast forward to 3:30 when we were let into the store. By this point there were at least 100 people behind us. My friend and I were pissed because we couldn't see any of the screen that people were playing on and the line was moving incredibly slow. We later found out this was because a. they were letting people play 2 2-minute rounds b. they were giving out free mario kart 8 flags and wii fit u headbands and c. they had the 3ds version of the game attached to some employees.
By the time we got to the front of the line at about 5:30, there was a good 200 people behind us (the line wrapped around the store!). The turnout was
crazy for my location.
By the time my friend and I were at the front they started limiting people to only 1 2 minute match so we were pissed off but whatever.
As for my impressions of the games:
The 3ds version surprised me the most. It played so fucking well it was awesome. The little single player stage I played was pretty cool and the lumiose city stage I played at the end was also cool as well. As people have said before it totally felt like city trial from kirby's air ride.
The wii u version of the game was awesome as well, but it didnt surprise me as much. I knew that it was going to be awesome (and it was). However, only playing it for 2 minutes I just couldnt get a feel for it. It looked awesome though and we played the boxing arena stage which I never knew you could go on the platforms to the right and left of the rink and the rafter above the arena. I'm definitely considering buying a wii u for this game.
I played greninja in both the 3ds and wii u version and I didn't like him too much honestly. I liked how fast he was, but he just didnt feel that solid to me (it could just be because of the short time I had with the games).
From a competitive point of view, I feel like this game could have legs. It's definitely a lot faster than brawl (and from what I've played, a lot more fun) although probably not faster than melee. I need more time with the game to really judge this.
Finally it was so weird seeing so many nintendo fans in one place. The demographic in the line was all over the place

.
All in all both games look like solid purchases, I just wish I had more time to spend with both of them to make more accurate judgements.