Couldn't really be let down by Luke Cage on account of the fact that I knew jack and squat about the character prior to reading "Alias." I will say that I loved him in Jessica Jones, and in this. That actor is just...he's so great and oh so easy on the eyes.
Regarding the show...
I liked it a lot, probably a bit more than Jessica Jones, but that's only really because I loved Alias a whole bunch.