It's definitely not a class for you if you are expecting: 1) Amazing DPS, 2) Amazing PVP, 3) Easy leveling. It's none of those.
Levels 1 to 25 were a real challenge for me. Most of it is due to figuring out new stats and dealing with a reinc debuff (-33% Vigor is a thousand times more painful than -33% damage/healing output). I died a lot in the beginning until I figured out where to place my turrets so that I wouldn't aggro extra stuff. The turret can't be recalled, unsummoned, or controlled in any way, until much later on when you get a ruby that allows you to set a specific target (30sec cd). The turret does not have extra aggro on its shots so it doesn't tank very well, even if you wait for it to attack first. AoEing on this class without a level or gear advantage is a guaranteed death. This class has no CC while leveling and is very squishy even with an offhand; if you accidentally aggro, you are dead.
Now the GOOD things about the Engineer are:
It's an actual support class. It's like what they tried to do with Bard, but failed. This class is for people that love to party and raid and work in groups. Most of your talents, rubies, and world mystery skills are based around supporting your team members' survival and DPS. I have not really PVP'd yet (P2P leveling is a bit empty), but from the looks of the available skills, I would say that the Engies are the flag defense or supportive DPS from the back lines.
For me? 8/10. More turret control would really help the leveling aspect. This is exactly the class I've been looking for.