The load 2/4 method is taking over, but I keep my caddies in my range box for stages that you have to go prone on. That seems to be the only downside to the load 2/4. I did pick up one of the EZ8 caddies that you can load 2 from, that wont fall out when you go prone.
If its any indication that you can go fast with the "old style" caddies Daniel Horner still uses them and he's doing pretty good.