I have used Caverject for my ED.  While I did have an erection that would not go down the first time I used it (which landed me in the ER), my main problem with it is that it seemed to give an unnatural erection and there was a loss of feeling.   I suspect that loss of feeling has been permanent; although I have feeling now that I use Viagra, it is not what it once was.   That may be due to age, but I suspect the medication contributed.   It does work, however, in giving hard erections when properly administered.