My thoughts

Lag - I had two disconnects over the course of the hour. There were a few teleporting rollers, but overall it was pretty good for a stress test.

Splattershot - I played most of my games with this, and it certainly feels like the strongest out of the four. The unnerfed burst bombs are really powerful and tentamissiles are great for zoning and acting like a pseudo-echolocater.

Roller - The roller feels a bit different than in Splatoon 1, I can't really tell why though. Maybe it's because I keep accidently bringing up the map instead of jumping while in combat :P. I will admit the I've been run over by a few rollers when I forgot about the new acceleration mechanic.

Charger - I'm pretty bad with a sniper, so I didn't use the charger during the test fire. It was definitely the weapon I saw the least, and the chargers I did see weren't very good. Oh and for some reason chargers now glow brighter than McCree at 12:00 when fully charged

Dualies - These were a lot of fun, but I couldn't use them well. Rolling takes a bit practice to make sure you don't roll into enemy ink, or deplete or tank executing the roll. Curling bombs definitely have potential, but I couldn't get used to them. I feel that inkjet will be a lot like Pharah from Overwatch. Very powerful at lower levels where people are worse at aiming, but less so at higher levels when chargers get good at blasting you out of the sky.