well here's my 2 cents on the topic...when you look at the glutes, delts, quads and the rate of absorption, there are a couple of things to look at...IM injections are the 2nd fastest rate of absorption in the body behind IV's...so in that essence, no, shooting it in a different spot on the body isn't going to speed up the rate at which the steroid is absorbed...the way i've always looked at is like this...your delts in comparison do your quads and glutes do not have anywhere near the same muscle mass nor blood flow as the delts just consist of small veins and arteries running through them...your quads have the largest mass of muscle in your entire body as well one of the largest arteries in your body (the femoral) which when shooting in your quads and glutes leads to 2 successes...
1. you are shooting into a muscle that is constantly used hence a constant large supply of blood flowing throughout that region
2. with the femoral artery supplying blood to all of your lower extremities and ultimately back up to your heart, you provide a great path in which the gear can be transported throughout the body
but most importantly, it's common sense...quads are obviously the largest muscle in the body...if your quads don't grow, you don't grow...that's the live and die by method of body building and muscle training...so when you shoot intramuscularly into that region, you are allowing for a dramatic growth pattern which will allow the rest of your body to ultimately grow as well...
and while others may have their opinion, that's my 2 cents on topic