Well. Not exactly what I was expecting, but at the same time it kind of was in a way.
*Spoilers and thoughts below*
Its wonderful when a writer can use multiple personality disorder in a show properly where you think something is real (or outrageous with whitehorses machine in this case) , and yet is able to add a spin to the scenario to have that outrageous event not ruin a show with the "I can't believe this shit, it's too fiction" type of situations.
If I am to be honest, the ending was perfect in the sense of wrapping the series up, putting a bow tie on it, and calling it a finished product while retaining believability.
If I am to be critical and selfish, I enjoyed the series so much that I didn't want it to end and kept expecting another twist (which there was a few in just the last 2 episodes) and I wanted it to go the more fictional route (time merging machine & "2 of you" paradox) over the expected multiple personality disorder wrap up that we got.