I ate there recently. It didn't seem particularly expensive for this kind of cuisine. It didn't seem particularly noisy.
I was impressed. The dishes were imaginative and had a high level of refinement. Two of the dishes I ordered were designed after cocktails--both a savory dish and a dessert dish. Although I initially thought this was gimmicky, both dishes were very good.
Of the four MIchelin-starred restaurants in SF I have eaten at in over the past two months, I would rank them like this:
I don't remember it being particularly noisy.
Unfortunately I don't remember it being particularly memorable, either. Very well executed, but I left my dinner having no real strong feelings (positive or negative) about the food. I'd hoped for a more compelling experience, given the price.
On the other hand, I went to RN74 shortly after it opened and thought it was fantastic.