I used to work at Riviera and spent a bit of time watching people play # 8, as well as having many opportunities to play it myself. It is clear that most pros go to the right fairway, but it is interesting to note that quite a few members still play to the left side. I would think this would be as much from habit as anything (since they played for years without even having an option).
Personally, though, when I would play the hole, my choice of fairway was dependent on the hole location. If the pin was on the right side, I went left, as I found the view more appealing and there was at least a perception that I didn't have to challenge the right side fall-off quite so much. Alternatively, when the pin was left, or especiallly in the back left, I would choose the right fairway. There is a knob just off the left center of the green that made visibility difficult if one was on the left fairway, whereas going to the right fairway allowed a clear view of the flag, and a shot that was on-line, even if short, was still on the green and not in the kikuyu.