Ed, I suppose 99% of the guys who try VED's have success with them. They may not be that satisfied with that success and the results, but they do have success.. They get an erection, which can usually be kept erect with the use of restricting rings. The type or cost of the pump isn't really a factor, as they all do one thing well, which is to produce a vacuum on the penis, which draws blood into the penis. If the veinous valves aren't working, either from lack of use, or lack of signal from the erectile nerves (which you don't have, since you has non- nerve sparing), then the rings will do the job. The biggest complaint is that with a 'normal', pill induced or injection induced erection, the erection goes back into the abdomen, which provides a more rigid penis, whereas the pump erection stops at the ring, which leaves a soft swivel point at the body. A good pump, one that I have recommend to guys here many times, and which I haven't had any complaints back about
is at the link listed below. It contains the pump and an assortment of different sized rings. Inexpensive, but medially safe and gives the same results as the $550 jobs. www.vitalitymedical.com/Product/Encore-Impo-Aid-Manual-Vacuum-Erection-Device-OTC-44010001.html
Hope this helps answer your question.