Okay, played a couple rounds as the Specialist... reasonably interesting Make Your Own Class option, basically.
Perks urge you towards small gun or large gun focus, heals(grenades) or more damage from grenades, etc. Seems like it'll be the most enjoyable class for me personally on pubs.
As it should be, all the other classes will outdamage the Specialist with their on Perk weapons. Good choices all around by Tripwire.
Hopefully they can work the Martial Artist back into the game at some point, I was really looking forward to flying around, jump kicking Zeds in the face, uppercutting heads off, etc.