I have often found that I prefer the 2:3 format as opposed to the 4:5 ratio, but have found myself framing to 4:5 because of the standard paper stocks. Of late I have found myself leaning back towards 2:3 AND 1:1
So, do I have a preference? No!
(BTW, I always crop - always. I tend to shoot a bit wider then what I intend for the final print if I can.)