I don't know how anyone could enjoy a dj set with perfect track selection but consistently poor transitions. Not that I expect a perfectly flawless transition every time, but if it's consistently awkward and jagged I find it too distracting. And I actually find it interesting when a dj can tell they've misread a crowd by dropping a "wrong" track---I like watching dj's get out of a jam.
Beyond that: it's dance music. Fewer breakdowns please, let the beat keep moving.
This goes for all types of dance music, mind you, not just psy djs, which I rarely see anyway.