So AFAIK there are no real 4-5* hotels in the main tourist district (Wat Pho, Wat Arun, Imperial Palace) - you either stay on the river (ie Mandarin Oriental) or in the business-y district (JW, HR, PH, etc) but this was a 5ish minute walk to the Sukhumvit MRT line which takes ~20 minutes to get to the Sanam Chai MRT station where all that is. Also could take the train to Wat Mangkon (~10 minutes) MRT for Chinatown. I found it to fine to take the subway out there hence my OK rating (you won't find a hotel right in the middle of the action).
I'm not sure what i was thinking when i wrote 2 trains, please disregard that - you can take just 1 train from Sukhumvit station to the major tourist areas. I think it's a little faster to take the Skytrain to Sala Daeng then get on the MRT from Silom, which is maybe where that comment came from, but I didn't think either way was particularly difficult to get to touristy stuff relative to the other options.