I have 2 brinsea ECO 20's. LOVE them. I hatch in them. If it is full it is a little tight for the chicks but I don't see it as a problem. They aren't going to be in there very long, so I don't fret over it. I have never owned another brand so I can't comment on them, but I am sold on the user friendly Brinsea!
I have the Eco 20 with the automatic turner, and I LOVE it. I had 16 of 17 eggs hatch in my first batch, and have 15 eggs in there now (due to hatch this weekend!). I have 2 themostat/hygrometers in it to monitor the temperature and humidity, and only have to add water once in a while to keep the humidity where it needs to be. I think it would be too crowded to hatch 24 chicks, but for the 16 I hatched it did just fine, and was really easy to clean.
I will eventually get a hovabator, or a cabinet incubator for hatching since they have more room for the hatching chicks, but since I'm not hatching out more than a few at a time it works just fine for me.
Everyone-- thank you so much for all your help and advice! I think I'm pretty sure I'm going to get the Brinsea! I can't believe the fabulous reviews on them- everywhere I look, I read good things.
I have the Brinsea Advance Ex and I was told I can hatch in it just as long as it's taken off the auto turner.
BTW, you might have better luck hatching chicks under a cat than the LG. Honestly, don't bother with those they are a nightmare! I had two just recently and they were both gotten rid of.
My suggestion is a Brinsea or HovaBator. They seems to be the easiest for newbies and provide great hatch rates.