If your 55 means you were born in 1955, we're the same age.
My surgeon saved both nerve bundles. I'm 9 months post-surgery and have ED. It is being helped with injections. ED oral drugs didn't do much for me. I suspect that it's not only "sparing" the nerve bundles, but what damage was done to the hugely vascular region around the prostate (the blood vessels that feed the area)...and your physical condition before surgery (ED or no ED, good general health)....IMHO. We're all different and will respond differently.
Others will offer more experiences, soon.
-Nov/Dec 07, March 08 and Dec 08: Severe perineum pain . Septra/Bactrim for 8 months for diagnosed prostatitis.
-PSA start of 2008: 5.3..... PSA June of 2008: 7.3
-14 DRE all benign or nothing felt
-TRUS Biopsy Nov 08: 5 of 8 cores positive GS 3+3 or 6. 30-65%. Perineural invasion.
-General Health: pretty good, 5' 10", 180 lbs, slim.
-Open RP surgery: May 09 both nerve bundles spared. Bilateral lymph node dissection performed. Discharged 48 hours after surgery.
-Post Surgery Pathology: pT3a N0 MX, extraprostatic extension (EPE), stage III prostate cancer, lymph nodes clear, seminal vesicles clear, Gleason upraded to 3+4 GS 7. EPE within surgical margins. Other than prostate and EPE, all tissue removed negative for cancer involvement.
-Bladder control within 48 hours of catheter removal
-ED ongoing but improving significantly with Trimix at 7 months post-op. Oral ED meds didn't do much.