I've shot pecs and biceps, and bi's do hurt... But it's a perfectly good site in my experience. On the pecs, I seem to bruise more easily there. When I do shoot pecs, I go with a 22g 1" needle and go about an inch and a half above the nipple, but about a half inch to the outside of the body (like at an 11:00 position on the right pec/1:00 position on the left pec, with the nipple being the clock's center). I go about a 15-degree downward aim, as my pecs aren't my thickest muscles. When I shoot bi's, I use a 20g 1 1/2" needle which I poke in about a 45-degree upward angle, piercing in just below the middle of my bicep, and to the outside of the big vein that runs up the middle. I have an upside-down "Y" vein pattern on my bi's, and the needle stick is right in the pocket of the "Y". That seems to get the shot right in the center ball of the bicep, and Bro it IS SORE for a day. Be prepared. You're aiming for the middle of most any muscle, or in the case of glutes, maybe a bit deeper than the middle.
I'd maybe be willing to do a video on injecting different sites, and upload it here, but I don't want it on my YouTube account. I haven't figured out if it's possible to host a video on EF's server, but if so, link to directions please?
Charles