Buy This: Toilets with Flat Tank Cover

This is a quick, learn-from-my-mistake tip.  If you're in the market for a new toilet, you want to buy one with a flat/level tank cover.  

About 18 months ago, we bought the Toto Ultramax 1-Piece toilet for a bathroom renovation.  It's a fine toilet except for one problem:  The tank cover isn't flat/level.  

Note the location of the bubble in the horizontal level

If you like to keep items, such as a tissue box or - heaven-forbid - reading materials, on top of the toilet, the sloped tank cover of this toilet makes it difficult as the items will slowly slide off onto the ground.

And that's the tip.  Unless you want to find your tissue box or other toilet-stored things on the floor morning after morning, buy toilets with flat tops.