I also am non-nerve-spared, but do have good results with injections and the VED.
My understanding of Viagra and the like is that they dilate the blood vessels. But the main tap is controlled by the nerves. If the nerves are functioning at least partly, then the pill will enhance an erection. But if the nerves are non-functioning then the tap remains firmly closed
Charlie, like you I could have the pills if I asked for them, but in view of their likely effectiveness, possible side-effects and expense, I haven't.
If your "fullness" is coming naturally then that is a good sign -- it means you have at least some nerve function, and pills might help. If it is coming from a VED, then keep doing that, but ease back when it starts to hurt.