I don't like Echo a lot, but I suppose I had to click "A lot" because I don't think "Not very much" suits my overall opinion on the character. I like Echo, just not a lot. Certainly not "Not very much".
He's got a good story arc but, considering the quality of prosthetics in the SW universe, I can't help but think he could do something about his arm. Being reductionist, he is a bit of a human astromech.