The RLD there is really worth a visit. I had nothing but great experiences the two times I've been... service levels generally higher than Amsterdam (same price), btw. Go and you'll see.
I've only been by car in past (thanks Wim!) but you can take the train (see
www.ns.nl for schedules) from Amsterdam to Utrecht Centraal. Then there are various buses to get you close. The main RLD is on
Zandpad. As Soylent noted, it's houseboats. Each kamer has a little footbridge over the water, quite charming really! See
http://journeyplanner.9292.nl/ for details about the bus... sorry I've never used it before so can't advise further. I know there is another, smaller RLD on
Hardebollenstraat (yes, I know. :-) ) which I'm not sure is worth a visit... I've never been and never hear much about it. Perhaps someone with more experience can chime in.