My perspective regarding the choice of translab or retrosigmoid is a bit different.
First of all, unfortunately hearing preservation is very difficult for medium-large tumors. Even with retrosigmoid, most people I know ended up loosing their hearing. So hearing preservation should not be the only factor when choosing retro, you should consider all possible risks.
The approach that I chose was to go with the best surgeon that I could find/have access to, and let him suggest the approach that he prefers. I had no useful hearing left, so hearing preservation was not a factor for me. Most of the surgeons I saw, suggested translab, two of them suggested a combination like Tod mentioned (which I had never heard of before). They also gave me terrible stats for facial nerve preservation. I ran away.
I ended up with Dr. Akagami, same as Nikki. I chose him, because of his stellar record, not because of the surgical approach he uses. In addition to what Nikki has already mentioned, Dr. A. explained to me that in his point of view, translab exposes the facial nerve too early, making it prone to damage. He prefers retrosigmoid, because it gives better access to larger tumors. Most surgeons will say that translab offers the best chance for facial nerve preservation. It all depends on the individual surgeon preference.
Bottom line, the surgical approach will not guarantee the best outcome, the skill of your surgeon will. So instead of agonizing over the choice of approach, I would try to identify the team with the best record, in terms of what is more important to you.
Marianna