I had the best experience at the...
I had the best experience at the Resotel when I went there with my girlfriend in December 2007. Service was super-friendly and great; e.g. we were initially put in a bungalow with 2 storeys, but then we told the manager that we had actually booked a private deluxe - so within 5 minutes we had our own bungalow. No problem. Breakfast buffet is standard and OK, but the local Thai food a la carte was both excellent and not overpriced. Only drawback were a few big noisy tour groups at that time, guess that happens in many places but showed that the place is getting popular. Although I booked via asiarooms.com it was not all clear what was included and what not, such as the transport from the hotel to the railway-station or the visit to the native mon-village.
Conclusion: a great gettaway (no cars, just boats) for a few days, Elephant Park, Tiger Temple, Mon Village or the bridge over the River Kwai or Eriwan waterfall are worth visiting. Mountain-biking in the evening is also a great option - we also enjoyed the relaxing massage, although it was a bit pricey. The natural setting between trees and tons of vegetation is superb and quite romantic.