I can't get enough of these characters. I wonder sociopaths can actually feel love. Or whatever he's feeling.
The answer is yes! They do feel emotions. The only basic difference they had is the lack of empathy. They gauge what other people feel by thinking about it, using cold reading or learning to interpret expressions, while they don't 'feel along' what those other people feel at the moment.
They also have more predisposition towards risk-taking and a higher tolerance to pain. This higher pain tolerance was correlated with the same pain center in the brain that regulated 'punishment' in learning, which was why they don't respond well to being punished to reduce certain behaviors.
With these few differences, the way they experience love isn't precisely the same as your average person, but they can and do feel 'good' or 'rewarded' when being around someone they love. This manga is a surprisingly good, if textbook, display of ASPD.