Following up on the Mincome Experiment, a couple of things stand out:

First, it appears to be structured more like a Negative Income Tax than a UBI. So we shouldn’t conflate the two.
Second, the data show there were some incentive effects, particularly among wage earners. That’s okay, we just need to acknowledge it.
Third, the affordability of such a scheme among, say, 350 Americans is highly questionable.
Finally, it’s not clear that the effects would be the same between a culturally homogeneous population in Canada and a heterogeneous population today. We’ve seen differential effects in social welfare programs between these two sorts of populations for traditional welfare.
http://archive.boston.com/news/globe/ideas/articles/2007/08/05/the_downside_of_diversity/