They're a lower band version of the Ego mate. The Etek 3 AM (when added with an emortal board) performs at about the same level as an Ego 8 or 9, if you remember how my ego8 shot at the first cpps when you borrowed it
Very simple internals, which is ideal for you scottyboy
lol
They use a poppet valve system, so they're a lot more air efficient and require less love and attention to run than your old pmr, although you do get a little bit more 'kick' with each shot.
Come standard with Zick kit and Cure (two?) bolt to help with efficiency and kickback.
You used to have the etek1 didn't you? It's basically a better version of that. Smoother shot, better efficiency.
As for weaknesses, it doesn't particularly have any. Like i said, if you get an emortal board then you get the nice LCD screen however, with a stock board you get an LED lights system, which can make changing settings a bit more difficult