The IC is within walking distance of sights like little India, the Malaysian cultural center, a number of mosques, CHIJMES, the Cathedral, Raffles, etc. From the Hilton and other hotels on Orchard Road, the only stuff that's walkable would be big modern shopping centers.

However, IMO a lot of the advantage of the IC would be their club lounge, so the hotel might not be the best choice or best value if one isn't Royal Ambassador.