Stayed at both last month, both in full harbour view rooms.
• The GS views are very nice but not as dramatic as the IC.
• Decor wise rooms were very similar. The room in the IC had a bathtub while the GS didn't.
• Club lounge in GS is great, nice food selection in the evening and booze. Can't comment on the IC one.
• Service I found very similar, both were excellent.
• The immediate area near the GS was nicer. The IC has massive construction site next door that is visible from the junior suites (we actually asked to downgrade to HV room to avoid any possible noise issues during the day)