Well, if it is emulation, its actually very good emulation. Remember that if it was simply emulation then the visuals would still be in low-res, but they are not. Look at it this way, the slowdown may be about the the same as in the N64 version, but at least you get high-res. It was free, so we cant complain to much, but the OoT port was a much better one, almost no slowdown.