I know one dude that hit the inside up farther by his groin and had to go to the hospital to have it drained after it balooned on him. Dumb ass newbie, I told him to use glutes for 3cc's at a time; and told him to shoot the outside and front of the quad. I guess some people are just retarded and don't listen....
I pin the teardrop (Vastus Medialis). Like any muscle it will probably hurt the first a little longer then normal but after a few injections it's like any other spot. I have no problem with 1-1.5cc's in there.
My left teardrop has a nerve running through it that shocks the hell out of me when I hit it. I know where it is now so I avoid it but it wasn't fun the first 2-3 times.
I use a 25g 1" but I could probably get away with a 5/8".
Personally, I like pinning in my quads, and always rotate between the outer and teardrop. I shoot 2 CC's of test e there, no problem. Even if done before bed I usually don't have lingering soreness the next day, mild if any.