VISTA is the new 4-metre wide-field survey telescope nownearing completion at ESO's Paranal Observatory.It has a single instrument, a very large near-infrared camera with a 1.65 degree diameter field, 67 Mpixels and 0.6 deg2 active detector coverage. Most of VISTA's observing time will be used by six Public Surveys recently selected by ESO.Comparing to possible future surveys from Dome C,a 2.4 m class telescope at Dome C would give slightly better sensitivity than VISTA at Y, J, H bands, but would require anunrealistic number of near-IR detectors to match VISTA's field of view.In the Kdark and visible bands the comparisonis much more favourable to Dome C, so a goodstrategy for Dome C surveys is to emphasise complementarityby concentrating on the Kdark band, and i-band weak lensingsurveys.