I would take the human. Now, here me out, there is NOTHING wrong with that amazing techno gal in my mind (insert mandatory bow chica wow wow) I'm sure she could show me a good time all the same.
I chose human because I don't see a downside. The robot girl can't have a child with me, and like most humans ... hey, I'm a narcissistic prick, and I want a tiny little me running around my feet one day. A child is a big relationship thing, taking that on together. Yes I could adopt, but the option is nice.
Also there is the psychological part of it. I know she is a robot. If it's realistic enough I can block that out for a bit here and there, but in the end I know its not human. I dont think I could connect to it as much. I would always be asking "Do I love her as much as I would a human" and even MORE insecure "Can she really LOVE me? How does she appreciate all I do for her, and what we share? She is just programmed that way. >_>" Granted, the human mind is just 'programmed' to function how it does, but you get what I mean... We, as humans, have a hard enough time accepting that all HUMANS are the same as us... imagine that step, trying to connect to something not even living.
In the end, whats the downside to having a real woman?