Unless there were problems prior to the RC, I don't think there is any reason to be considering implants at this stage of the game.
Nerve sparing can take anywhere from a few months to a few years to work. Often, feeling comes back quickly as well as the ability to have an orgasm (dry) but the erections will not be firm enough for penetration.
Some people find the pump to useful, others have reasonable luck with Viagra or Cialis. Then there are others, such as myself, that the shot seems to work the best.
Mike
Age 54
10/31/06 dx CIS (TisG3) non-invasive (at 47)
9/19/08 TURB/TUIP dx Invasive T2G3
10/8/08 RC neobladder(at 49)
2/15/13 T4G3N3M1 distant metastases(at 53)
9/2013 finished chemo -cancer free again
1/2014 ct scan results....distant mets
2/2014 ct result...spread to liver, kidneys, and lymph...