W Location definitely superior to Sheraton. No contest.
W location is superior.
1) Subway system (El Golf station) is only 2 blocks away.
2) W has probably more than 20 places to eat within 3 blocks. While true that a FEW of these are US chains (Friday's, Starbucks etc) the majority are chilean places. These range from the very affordable Tiramisu, Domino (Chile's best sandwich place), or Tip Tap, to very old and traditional Santiago downtown restaurants that have moved to this area (Cafe Torres, Pinpilinpausha, Due Torri, Da Carla).