I had a vasectomy 36 years ago. I never felt any different before or after, as far as orgasm went.
During prostatectomy, the surgeon will remove your seminal vesicles, the tubes that carry sperm from the testicles to the urethra. The vas deferens, small ducts that store sperm, will either be removed or tied off. The result is the loss of sperm being stored in the vas deferens and the seminal fluid which is a carrier medium for the sperm from the vas deferens, and in most cases the pre-intercourse lube most of were accustomed to seeing. A Vasectomy stopped the sperm at the lower end of the tube, and surgery stops it at the top end of the tube, in both cases, the sperm is absorbed by the body, to no ill effect.
Dry orgasms after surgery is the norm, and most guys report a change in how they feel. I know mine started as weak, internal contractions, and have now matured into almost as good and sometimes better intense ripple contractions. Some report much more intense and longer lasting ones. Mine are much more pleasurable now. Before, most of them were of the 'ho-hum', thats done variety.
4/19/07 PSA 7.6, referred to Urologist, recheck 6.7
7/11/07 Biopsy- 16 core samples, size of gland around 76 cc. Staging pT2c
7/17/07 Path report: 3 of 16 PCa, 5% involved, left lobe , GS 3/3:6.
9/24/07 (Open) Retropubic Radical Prostatectomy performed
9/26/07 Post-op Path Report: GS 3+3=6 Staging pT2c, 110gms, margins clear
10/15/07 ED- begin 50mg Viagra and Vacurect pump nightly, Fully continent
1/14/08 Caverject started/stopped, aching. 2/24/08 .5ml Bimix started-success
5/7/08 ED- Viagra, pump, no response- Trimix .075ml continues
Post-surgery PSA's: 3 mt:0, 6 mt:0,