Definitely the 50 is easier to adjust. I make one side higher than the other and let the chicks figure it out. Love mine! Plus I think it helps with weak legged chicks (IMO) since they stand a bit to press against the plate. Same concept as putting them in the cup - making them work a little.LOLIf you hatch 50 chicks, get the ecoglow 50. It looks like the height adjustment is much better. One tip with the 20, if you hatch small chicks, leave on side off and make a tilt for the little ones to go under and still touch the top.
Turning the lights off at night as you said, another big advantage. And you can put it anywhere- my chicks are currently in a big cardboard box so I can transport them to the barn after a day or two - I'd never stick a heat lamp in a cardboard box.
Then there's the power savings... and I can put 'special needs' chicks under it and have fewer worries about pecking since they are hidden under the plate.