I played this some more and enjoyed it quite a bit. I got 2 Devastator and Trickster to 7 and Technomancer to 6. The Devastator is the best geared of the lot with all blues with decent mobs on it. I play with him on Tier 5 and everything is pretty much a walk in the park. The others struggle in some encounters in Tier 4 but don't have great gear.
Gear matters a lot which is really nice to be honest in a looter game. You want gear to matter a lot and it does here. The difference between blue gear+ and green gear is night and day, and to be honest the game starts being fun when you start getting blue gear.
I have mix feelings with their attack to regen health style of play. It doesn't always work well and forces some class into a very specific playstyle otherwise they won't heal at all. For example the Trickster and Devastator cannot really do the snipe a few targets before entering the battlefield because if they get hit, when they do need to get into close range they are at disadvantage. I found it to be better to just jump right in with them from the get go which I find limits their playstyle a bit. The other issue, is that while the system works well most of the time...I feel we're missing a "oh shit" way to get health back when you screw up, it could be on very long cooldown but I just missed the ability to get a big heal once in a while, the regen is in some circumstances to slow.
The game is far more fun with others(then again most games are) because there is some pretty synergy between the abilities. My devastator Earthquake on targets frozen by the Cryo Turret of the Technomancer is pretty deadly. I expect the game to have a lot of fun combos later on.
The writing isn't spectacular but I am enjoying the setting and story so far, even if it's not the most original.
I'm definitely getting it at release, if the reports of a 25-30 hours main campaign and 2-3 times that if you do all the side content is true...that will be worth of the game for me even without the endgame content or playing more than 1 class.