I'd like to thank everyone for their input. I've been on the road and haven't been able to get back to the forum untill now.
I think I've found the answer ... use half a pill! .... Seems to work for me with no side effects.
One commentor indicated that at 18 months you would probably have all the ED improvement you could expect ... I do not think this is correct. I've spoken to guys who have had improvement after 2.5 years! Pills didn't work for me until after 14 months and now they work real well (except the side efffects). I plan on continuing penile rehab (use of low dose pills to increase oxygen flow to the penise) for 3.0 years or until I get regular nocturnal erections ... which ever comes first.
Concerning injections ... I really like them and recommend anyone who has ED problems (from surgery) give careful consideration to the use of injections per Dr. Muhall's guidance (see his book on Saving your sex life). On the use of the injector ... I tried it but quite ... its much easier to just inject.
Thanks for your suggestions.