Well I tried the ventro-gluteal site once both sides now. I'd say the results are mixed. I'm pretty sure I have the right spot. On one side, I did have a little nerve pain going in, but not bad enough to make me reflexively pull out the pin. The other side was a bit easier.
I'd say I got a fair amount of PIP on both sides compared to quad or delt... pretty noticable when getting up and lying on my side. I'll probably try it a few more times at least to see if I get used to it more.