Well, for one thing, I draw with a larger gauge, 20g. I do my injects with a 25g with a 3cc syringe.
The insulin pins are probably easier to shoot from a 29g because you are using a 1cc syringe. The smaller the syringe, the more pressure it puts on the liquid. For example, if I used a 25g pin with a 5cc syringe, I might run into some problems. But with a 3cc, none.
As for the amount of time it takes me, I probably shoot too fast. I have to pace myself, and for 3ccs of gear, it only takes me a minute. I shoot for 1cc/minute, but it never works out that way.