here is a quote from an article on the subject:
from Dr Bruce Garber
The scrotal and infrapubic approaches each have advantages and disadvantages. The scrotal approach provides excellent access to the corpora, which is especially helpful in patients with corporal fibrosis or Peyronie’s disease, who may require penile straightening procedures or extensive intracorporal dis- section. It provides excellent access to the scrotum, so that the pump can be fixed in place, and usually allows the procedure to be done with less tissue dissection than that which is required via an infrapubic approach. The scrotal approach allows cylin- der insertion with essentially no chance of injury to the dorsal penile nerves. However, the scrotal approach requires ‘blind’ transinguinal reservoir insertion, which may be difficult, risky or impossible in patients with prior hernia repair with pros- thetic mesh, cystectomy, renal transplant or morbid obesity. The infrapubic approach requires more tissue dissection (through the infrapubic fat pad) and care must be taken to avoid injuring the dorsal penile nerves during cylinder insertion or replacement. However, it allows reservoir insertion into the prevesical or extraperitoneal space under direct vision.
article reference:
Inflatable penile prostheses for the treatment of erectile dysfunction: an update Bruce Garber MD
Expert Rev. Med. Devices 5(2), 133–144 (2008)
Personally, I would not want the infrapubic since the tubes course over the top side of the shaft, so a woman might be able to feel them against her clit during deep intercourse, also, there are more numbness issues, also, the pump does not get placed as preceisely in the scrotum with the infrapubic -- and for many, the pump position is a source of discontent from us bionics.
So, I am a big supporter of penoscrotal -- but, it is better to go with a super talented high volume surgeon and follow their preferred approach.