Holiday Inn Silom is almost at the (river) end of Silom, and so not convenient for the Skytrain. I stay there regularly and take one of the many buses (virtually every minue during the day) from outside the hotel up to Sala Daeng to connect with the Skytrain for about 10 baht. A taxi is only about 40 to 50 baht depending on traffic. If the traffic is choked you can taxi or walk to Sathon (about 10 mins) and get the Skytrain from there.

If you are in an executive room you get access to the executive lounge which is good value - complimentary breakfast (nice selection), afternoon tea, and in the evening unlimited drinks with high quality canapes from 6.30 pm to 8 pm. Whilst not in the best location and certainly not one of the most attractive buildings, with the executive benefits I think it is one of the best deals for 4 stars in BKK, especially if you can get it for $90 per night.