So, how do I level it up?
Not sure what to say as my Engi rocks with maps, raids, metas, whatever. Mobs die just as fast as any other spec really although rifle can be tad weak. Remember, with Engi its about swapping kits and such, not camping one skill over and over. Now Mesmers, yes, they kinda blow in dps in open world but I am actually have some good fun as condi.
So I would say stick it out if you like the class, otherwise don’t bother.