I bought MS Store and FS2020 Deluxe.
Which level you should buy depends on which airports and airplanes you
want to fly.
Right now, I fly the Cessna CJ4 mostly and is my favorite.
The Cessna Longitude only comes with the Premium purchase.
The Longitude is getting a lot of praise.
Now, I have to buy the full Deluxe package to get it.
So, I probably will not. Should have bought the Deluxe back then.
Steam users are happy also. But I have never used it.