Which 300x300x400 printer?

[curious aardvark]

the nereus is just a ender/creality clone.
one z axis motor, bowden extruder, central rail mounted bed.
It's pretty much an ender 3. Even angus on makesmuse had trouble with the ender 3 :-)

The wanhao is the only one that has dual z screws, direct extruder and a properly mounted bed - on a gantry that wide, dual z screws matter.
Plus has bl touch.

In the 3d printer world, you don't necessarily always get what you pay for - but more often than not you do. For the build volume, build quality and features, the wanhao is head and shoulders above the others.

You're stuck with cura for them all - but wanhao has made their own customised version - which, hopefully is better than the bog standard piece of junk. It should have the bed levelling built in - which saves you a lot of hassle.
I'll always recommend simplify3d, but at least wanhao have made an effort :-)

Also this is your first printer - the wanhao is the only one there that you shouldn't need to modify and hopefully won't give you hassle in all the areas ender 3 style designs usually do.
Plus wanhao have a good reputation for customer service.