I have read more about this issue at this point than I care to for a long time! Well, no, I exaggerate. But it's just that opinions on this tend to be highly partisan, with Bicycle Quarterly doing the majority of "low trail" promotion.

It is interesting to me, that most people I know in the real world who have ridden low trail bicycles, report disliking the handling - often, intensely so. This is a sharp contrast to how much this feature is praised in BQ.

The lowest trail bike I own has 54.5mm trail, which is really neutral. It handles splendidly loaded and unloaded, as does my Rivendell with (I think) 56mm trail. The Rivendell I have ridden with close to 20lb on the front, and it acted indifferent to the weight. But I am curious to try lower and compare.