Honeywell - TrueSTEAM 9-gallon humidifier

If you have hard water at all I would suggest avoiding a warm mist humidifier. These are ultrasonic humidifiers and eject the entire water droplet, including any dissolved minerals, into the air. This can lead to a lot of dust as the minerals settle on surfaces. You also can't use water treatment products in them since it will put those in the air so keeping them clean is very important. Steam humidifiers santize the water by boiling and the minerals get left behind. Some of the newer whole house steam humidifiers use a replaceable canister to handle the mineral issue but many just require you to clean it (vinegar works well for this). I used to use a central steam humidifier (Honeywell Truesteam) and it worked very well. Unfortunately it broke and can't be repaired so I'm not using it anymore. Some of the downsides of steam are that it does add heat to the air and is capable of greatly over humidifying if you allow it to. So ideally you want a model with a built in humidisat so you can keep things under control. You also need to lower the set point as it gets colder out, or have one that uses an outdoor temperature sensor and does this automatically, to avoid condensation and possible mold issues. Steam humidifiers also use the most electricity since they are literally boiling water. If you don't want to use steam I think cool mist is a better option than warm mist. These are the kind that use a wicking filter and a fan. The console models can actually add a lot of humidity to the air and you can safely use water treatment products with them to keep the water clean. The minerals also get left behind in the wick so no issue with dust.

Both April Aire and Honeywell work fine pick whichever fits your setup better. Main thing is your electrical steam units need more juice so check if your transformer and wiring can handle it before you start. Make sure there's a shutoff on the water line or add one. Taking the old one out without screwing up the ducts is the worst part so just take it slow there. Steam to steam swap isn't too bad though follow the instructions and don't rush it.