My first incubator was a Hovabator forced air model with the autoturner. The turner was the only thing about it that worked well.
I know a lot of people on here are very loyal to their foam incubators and have good results with them, but I found it to be extremely unreliable, and I was constantly fighting with it. Unless you keep the temperature in the room where it is located EXACTLY STABLE, the incubator temperature drops or spikes out of control in short order. And, the business of putting water in the little troughs in the bottom means that the incubator was constantly either dripping wet, condensing on the windows and dripping down when it was filled, or in a day or so, bone dry and in need of a refill.
To be fair, I think most of the problem with the temp was in the fact that it used a metal disk as a control element, and this was adjusted to the ambient temperatue when you set it -- no flexability or "intelligence" in the system. When the room temp changes, the incubator is no longer set at the right setting, and the temperature inside either drops or spikes. Newer models with electronic thermostats or digital thermostas no doubt would work better, mine was purchased around 1992 I believe, it's been a while, anyway.
I did recently remove the disk and turnscrew from mine and replaced it with a Zilla brand electronic controller purchased at
Petsmart for $50, the kind with the remote sensor and outlets for heating appliances -- I put the sensor in the incubator at egg level, set the temp for 99 on the dial (not digital either, but it said it would keep the temp with +- 1.8 degrees, which should be close enough), and it did keep it pretty consistent temp wise (I just put some unfertilized chicken eggs in there to test it). I was thinking I could use this as an emergency backup incubator or as a hatcher if the need arose. Seemed to work OK, but, this still doesn't solve the humidity issues == good thing at hatching you basically need it steamy.
So, this spring I treated myself to a
Brinsea Octagon 20 Advanced Automatic with the autoturner and the humidity pump. It is a great unit -- I hatched duck eggs and turkey eggs so far, and I just set 24 button quail eggs in it Friday night. Yes, it was pricey -- about $450 with shipping -- but it is SO simple. All digital, all programable/adjustable, high quality plastic parts, easy to clean. I especially like the humidity pump -- SO many posters on here have issue with humdity levels during hatching, and make it sound like it's VERY hard to get humidity high enough during a hatch, especially if you open the incubator. Well, with the humidity pump, the
Brinsea will adjust to any desired humidity level in like 5 minutes, and if you open the unit and the humidity drops, it's right back up to the desired level in under 5 minutes again.