The toilet works fine. The Champion 4 has a 3" flush valve and the trapway is a little over 2"
It's fairly long and heavy. The end of the bowl sticks out a long ways from the wall. Not the best choice if you have a small bathroom.
Because of the large size of these, they are also very heavy. I'm 200 lbs, and compared to other brands, it's a beast to pick up and carry.
You will need to supplied socket to install the seat.
It's adequate, but there are better choices out there. Quality control is not the best, but you can find some that work well enough.
My feeling is that "if" you are looking at American Standard, the Cadet series is better. They have a Cadet 3 and a Cadet Pro. I sell a few of the Cadet Pro's.