These big massive floating RVs can be found on and docked along the backwaters of Kerala. To answer the title, are it worth it. Maybe on a postcard you send back to your grandmother.
But I don’t believe they are unless you plan to stay out on the open waters as they can’t maneuver through the tight and leafy smaller routs where life seems to descend back 50 years of tranquil simple living. As much fun it seems to be floating around on one of these house boats, I can assure you renting or hiring a private tour guide to take you through the skinny canals and narrow passages is well worth the money in comparison.
My advice? Get yourself a simple guest house for a few hundred rupees max (5-8 USD). Set up base camp, drop your stuff and go venture the back waters on a narrow paddle or small engine boat that you can rent for another couple hundred rupee. Then when the day is over, grab some food from the local markets, wander, and retire back in your guest house bed.
I may be bias though, I was lucky enough to find a room in a house way deep in the backwaters away from the streets. A hired tuk tuk (taxi) had to go through some farms and skinny roads where I was eventually dropped off and had to walk another 1/2 kilometer along the banks. Not a bad place to forget about ticking time and the hustle of India. where it is pitch black at night and the sound of bull frogs and crickets chirping put you to sleep at night.