I have been using the MG 16/4 mixer for a month now. I have done my best to distinguish between tracks recorded through the Yamaha and through a Mackie VLZ Pro 1202 that I rented 4 months ago for a week. There are subtle differences, but neither one sounds any "better" than the other (ie. the tracks are not identical, but neither one is superior to the other). I have a Behringer 602A that I have lived off for the two years prior to buying the Yamaha, and the difference in the tracks recorded through the Yamaha or Mackie are much nicer than the Berhinger MX tracks.
I still intend to buy some quality stand-alone pres in the next year, but for the time being, this Yamaha mixer is great, and I have no qualms about keeping it in the mix for a good length of time (recording to DAW).