for the delts all i can say,it will get sore the next day but nothing that will keep you from training...you get used it...it is well worth the little bit of soreness you endure...especially when your delts blow right up...
i've been using eq in each bi for 10wks, 1cc in each/wk. arms were up 1/2 inch by wk 5 or so and have stayed the same since. seems like fascia stretching to me. used 23g 1", no probs. definitely worth it.
I dont feel a thing in the triceps. Delts hurt the next day or so, and biceps hurt right after injection for a short period. Quads dont hurt at all. This is for me, so you might be different.
delt and quad injections are pretty painful and can make you really soar, I guess I really didn't try shooting in them a second time so I couldn't get used to it but as far as Eq goes I don't think it will make that big a difference in site injections even when using a thinner, smaller needle
I personally love shooting EQ into the tri's. It's my favorite place to shoot. If site injections don't work, then I guess it's just coincidence that my tri's are the strongest, best developed muscle.
And if you like the kick EQ gives in the arms... you GOTTA try Fina.