I have a Hovabator 1588 also, love it.  Very roomy, nothing to set, it comes preset.  If you get the cheaper one, you will miss the fan.  Which comes in very handy for keeping your temp and humidity regulated, as well as drying chicks quickly after they hatch.  I had purchased a LG still air previously.  Then upgraded, should have spent the money on the Hovabator in the first place.