How many eggs do you want to hatch at a time and what kind of eggs (chicken, quail, pheasant, goose)? How many times a year do you plan to hatch?
There are three basic types of tabletop incubators.
Still (thermal) air – These are normally the least expensive. A lot of chicks are hatched in them but they are more difficult to use. Since hot air rises you have to be careful about how high in the air column you take your temperatures. Humidity can be a bit more challenging to manage.
Styrofoam forced air – These are the mid-range in costs. It’s the kind I use, a Hovabator Genesis 1588. Typically they work really well but they require more hands-on to manage humidity. They are generally not a “set it and forget it” type thing. Since they are Styrofoam that are harder to clean between hatches compared to the hard plastic types. I only hatch two or three times a year so I’m OK with that. If I hatched much more I’d probably upgrade.
Hard Plastic forced air – You are getting top of the line here and will pay for it. Different ones come with different controls and manage humidity differently, but you are getting to the “set it and forget it” situation once you get them set up right. You may just need to put water in a reservoir and it adjusts humidity automatically. That gives you fine control. If the humidity system is reservoirs in the bottom of the incubator it takes effort and time to make adjustments and these are often fairly coarse adjustments. If you are going to be a hard core incubator the finer controls are probably the way to go.
I strongly suggest an automatic egg turner with any for these. You can turn by hand but that mean you commit to being around at different times of the day every day. It’s just tremendously more convenient if you don’t have to worry about turning.
I don’t care if you get the cheapest thing out there or the absolute top of the line, do not trust any thermometers or hygrometers that come with the incubator or that you buy separately until you check them out to see if they are reading correctly. Do not trust any factory preset settings. They are not always correct. Look at how easy it is to adjust temperature if you need to tweak it. A dial of some type is usually pretty easy to use. I have an older model 1588 and this was a pain in the rear. The newer models are much better in this.
When you get the incubator plan on having several days to play with it before you start eggs. Run it and see how it holds temperature and humidity. Learn how to make any adjustments you might need to. Do this exactly where you plan to use it. Even if you just move it across the room you may find that some of this stuff changes.
I’d not consider anything less than a forced air Styrofoam with automatic egg turner and that is if you are only hatching a few times a year. Hovabator Genesis are pretty good examples of that. If you are going to hatch much more often look at the
Brinsea models. They are probably going to be worth the cost to you.
If you are planning on hatching a lot of eggs at a time, you might want to look at the cabinet models. I don’t have any experience with them.