re: Were waterbeds good?

YES! Excellent. Best bed/mattress I ever owned (might now go back after thinking about it.)

You'll love it.

Had a higher end Cal King for 20 years. Even bought one for the babies / kids. (it's a sensation of being womb-like; warm and reduces aches, pains and pressure points so you sleep MUCH better & deeper.) You can even slightly reduce the temp in warmer weather if you "sleep hot".

Peeps who disliked the water bed experience probably didn't like them for good reason. It must be filled properly (back-lumbar support), if they lacked baffles they sloshed around too much; and yes, the thermostat-heater must be dependable.

So...You need a "baffled" system that restricts
that annoying sloshing movement.

IF you do this, purchase a quality thicker gauge liner; a baffled unit that has minimal movement; and make sure your heating device / thermostat are also quality. You'll also want "railing" pads on both side of the bed. A Waterbed is NOT a complicated process.

PAY THE PRICE for a premium unit -- don't cheap out. FWIW I've tried all of the traditional mattresses types; they don't come close to a waterbed. Go for the gusto -- and good luck.