Removal of textured ceilings 70s era

[Mitchell Litam]

Hello,

I looked on the forums for this and the only one I saw was from 6 years ago.

I am trying to remove the ceiling texture from my ceiling to return it to flat.

It is not popcorn ceiling it is the drywall mud that looks like its been slopped on.

I have seen two different methods. One being using a drywall sander on the ceiling and the other is to level all of it with drywall mud with trowels and to make it smooth. The third option is to drywall over all the ceiling but I dont think I am going to add any lightning so want to avoid this option as it will most likely be the most expensive.

The house is just over 3,000 sq feet. I dont really care but the wife wants it done and we are doing the work ourselves as I am sure it will be $1-2 sq/ft. 

Does anyone have any experience with this? Which method sucks less between sanding it down or filling it in with 45 minute compound? 

Note: this is not a flip this is our house.

Thanks for all your input!