I think so too. The last thing he needs is to wind up with a woman with a whole bunch of unresolved issues. I think Nikki was still carrying a lot of baggage from her last relationship.
I'm hoping that he chooses Melissa, at this point. The more I see her, the more I think they might be a good fit. But, whoever he picks, it is for real. I saw a post-show interview where Jason says he is "completely in love" and "they" are engaged. I am happy to know that.
I just watched the Bonnie Hunt interview, very funny, and he confirms he and his chosen are engaged.