Depending on your expectations the Boutique Raft Resort can be the choice for you. Its located 50 kms up from Kanachaburi so it's good for the excellent Hellfire Pass, Sai Yok or Erawan NPs and other attractions, if you want to stay around the touristy bridge then choose something closer. The resort is all about the river and you can really feel it by staying in the raft rooms. There is hot water, A/C and decent beds with a super river view and decks that you can sit out and even wade in the water. Yes the walls are thin and you can hear next door's coming and goings, yes the decks are common space but its relative to the price paid. People chatted and the rhythm of the Thai voices coupled with the distant karaoke in some other river restaurant told you where you were and lulled us to sleep. The main building is the large open air reception and the restaurant is on the upper floor. The food is average at best however the staff are Thai lovely, all smiles and miscommunication, always charming and disarming, how can you get short with them? It's a little hard to find so use the GPS coordinates and soon you'll be welcomed with a cold drink and sawadee-ka.

This place is a great alternative to staying in Kanchanaburi itself for 4 reasons:
1. It's right near Nam Tok station, so you can travel by train from Kanchanaburi, over THE bridge and along the original WWII route, including the most incredible section where the track simply hugs the side of the cliff, right to the end of the line - Nam Tok. This is about 60k from Kanchanaburi. If you inform the hotel of your train arrival time, they will send a car to collect you free of charge.
2. The main reason for visiting the area at all is Hellfire Pass Museum and walk. Staying here means you're within 20 minutes of this.
3. Kanchanaburi itself is full of loud karaoke bars and is a bit of a dump. The Boutique Raft Resort is peaceful - if you can afford it, I recommend the River Kwai Suites - that way you are actually on the river itself, and you have a lovely verandah on which you can sit with your coffee, soda or something a little stronger, watching the world go by along the river!
4. The hotel staff were helpful, and it was easy to arrange trips. For example, we arranged for the driver to take us to Nam Tok, keep our baggage in the car while we travelled along the most exciting part of the track, meet us at another specified station, take us to Kanchanaburi so we could photograph the same train crossing the bridge, take us to the allied cemetry and then drive us to Bangkok all for 3,500B. She's a careful driver and speaks English, too!

We stayed in a raft room for three nights. It was very well presented, clean and a great experience to have your room float around on the river.

The staff where very friendly and could not do enough for you. We booked two tours through the hotel one of the seven tier waterfall and the other for Hell fire pass. The were well priced for just the two of us.

The only bad point was that you are 60 km from town which meant you could only eat at the resort. The food was nice just lacked a little flavor.

The first thing you need to know about this place is that it is not in the town of Kanchanaburi...it's about 50 kilometers northwest of the town of Kanchanaburi. We actually didn't know this, but it turned out to be just fine. It's actually closer to two the things we wanted to see (Hellfire Pass and elephant rides), so it turned out great.

We rented a moped and drove out there, but the hotel does have a shuttle.

The hotel is actually ON the river. They have "raft" rooms that are floating on the river. It's a pretty cool experience. There were several families staying there and all of the kids seemed to have a great time.

You can book various activities through the hotel, but they are a bit pricey. I'd recommend, if you have your own transport, to go to things on your own. Get a good map and drive yourself. However, for convenience, the package deals from the hotel are OK, too. The more events you book, the better the price.

We really enjoyed staying here for one night. I'm not sure I'd want to stay much more that two nights. It's pretty much right in the middle of the jungle, so that was neat. If you have trouble with the sound of water all of the time, they have rooms up on the land, too.

The actual facilities in the room were pretty meager. It's pretty much a rustic cabin on the water. Not a luxury place, by any means. They have a restaurant, acceptable food but nothing spectacular. We actually walked down the road for one meal and went to a family-run restaurant that had great food. Breakfast was pretty good, though.