I have noticed that moving through pot sizes gives better root development within the pot sizes. If I move straight to larger pots, roots tend to amass at the edge of the pot with less root development in the centre. Also, soils compact and change over time. Even if you have potted into large pots, you still need to re-pot them (into the same pot) so that you can minimise the anaerobic build up at the bottom of the pot (and give fresh nutrients). If you move directly to larger pots, you will initially see a greater growth rate, but over time you will notice that moving through pot size will give better growth pattern and overall performance. I have 1000's of pots full at any one time, I always move through pot sizes even with all the added work...