One major drawback with a 25guage: VERY slow push with an oil-based compound.
If your in a good position (like right upper thigh for a right-hander) it's no big deal, but for the left thigh or glutes it's an uncomfortable position for me to be in that long.
Per bravo, I've been trying the vastus medialis at the lower quad- a very easy, comfortable push. First time or two I was very sore there, but now it seems just fine. Plus, I can do it right at my desk at work without having to drop my drawers