I've never used the injectable variety. I considered keeping it, and giving it a try, because I'm curious as to whether or not it has any different (read: better) effects. While I've never given myself an injection, the directions were clear. It's a subcutaneous injection (as opposed to an intramuscular), which I've done with vaccinations on animals...although never on a human and certainly not myself.
The downsides? I don't want to learn/practice doing something that might be painful when I'm in mid-migraine, and the kicker: it's only two doses. The pills are nine, and the inhalers are six. While I might only need two doses between now & the next time I can refill, I can't count on it. Besides that, I'm just not really fond of needles. Not squeamish, I just have an aversion to hurting myself. So back to the pharmacy in the morning.