I was in similar situation last month when I took my parents to BKK for four nights. We split the four nights between the Oriental and the Peninsula.

IMHO, service at both hotels was outstanding and efficient, far better than one would find at any hotel in the U.S. I will say that the service at the Oriental does exude a bit more charm, grace, and warmth but service at the Peninsula is more consistent.

At the Peninsula, we reserved a Superior room for $260, including breakfast and rollaway for third person. We were given a complimentary to a Deluxe room upon check-in. I inquired how much an upgrade to a Deluxe Suite would cost and they said $60.

I took the upgrade and was not disappointed. For $320, we got a very nice suite with wrap around windows with nice views of the river. The living room had very comfortable and plush furnishings. There was a dining table with four chairs. There was a guest bathroom located near the foyer. The suite was so big that it had no problem fitting a rollaway.

The breakfast was one of the best I have ever had in my life. Pastries and dim sum were excellent. The divine french toast contributed to my weight gain.

At the Oriental we had a Superior River Wing room plus a rollaway for $350 including breakfast. The breakfast was good but not as good as the Peninsula. The room was compact as it was so a rollaway made things very tight.

In retrospect, we should have stayed all four of our nights at the Peninsula. We had a far more spacious room with gorgeous views. The service was comparable at both hotels. The breakfast was superior at the Peninsula. The health club at the Peninsula is a very fine facility where as the one at the Oriental needs renovation. And the Peninsula was less expensive.