PS 3/6 much tougher than PS 2/4, short-tables?

[Wynton]

I'm wondering if there is much difference in quality and style of play at the six-max tables at pokerstars, 2/4 and 3/6. Anecdotally, I've heard that 3/6 is much tougher (and that the leap from 2/4 to 3/6 is greater than the leap from 1/2 to 2/4, at least at pokerstars.)

I can see that this might be true because ps does not offer anything in between 3/6 and 5/10.

Any opinions?