Yes, they still make the heated ones. Expensive though!
Larry, I'm using the milkbar feeders for group feeding, one with compartments & two without. The compartments seemed like a good idea because provided the calves don't bunt each other off they each hold about 2 - 2.5 litres so you know for certain that the calf has had that much even if they're a slow drinker. In practice - they bunt each other off and shove around and the compartment feeder is more of a nuisance than otherwise (because milk is left in one or two of the compartments when all the others and the two other feeders are all finished - I can feed around 30 calves in a group with the three feeders). I'll pick it up to go and feed young calves sometimes if there's one or two I want to watch.
My calves are grouped on age and I've never seen cause to worry about slow drinkers - last year I pulled one out and fed her in a pen on her own and that's the only time I've ever done that in 14 years of raising calves. I don't wean till they reach an appropriate weight, so a slower growing calf may be given an extra week or two after the bigger ones the same age have been weaned.