Not bad..the SoT isn't bad, but the idle time is pretty bad. Is this Kitkat or Lollipop or Marshmallow? If it's not Marshmallow, I'd try it out (you'd need to download a MM ROM). I bet Doze would help with the idle times.
I had an M7 back in the day it released. I loved that phone, especially the speakers and the design. It is to this day, one of my favorite designs. It was also the perfect size imo.