FROM EXPERIENCE: Drake is the better choice
In 2005 I bought my first Drake for the main bathroom. Since then, it has functioned perfectly and still retains all its original parts.
In 2008 I painted and redecorated my first floor half bath. To save some money, I bought a Cadet 3 at a box store. If you read my posts, you will see that it took 3 tries to get a bowl that was marginally acceptable. I had no issues with the quality of the flush of the Cadet 3; it never plugged and it rinsed well. It also retained its original flapper. But I was not completely happy with some blemishes in the glaze and a slight ridge in the bottom that was not smoothed out. However, since it worked, I put up with them.
HOWEVER, in the past several months, we noticed an odor coming from the Cadet 3 bowl (read my posts and observe the photos). We found defects under the rim that looked like peeling or large voids in the glaze, plus some cracking in between the water ports.
We went to a PLUMBING SUPPLY HOUSE where I bought the first Drake and replaced the Cadet 3 with the Eco Drake. This half bath is the one I use before leaving for work in the morning, and the Eco Drake gets heavy duty cargo to ship! I have found no difference between the flush of the 1.6 Drake or the Eco Drake, nor have I had any problems disposing of "liquid waste" in either. It all goes down the first time every time.
The lady who sold us the Eco Drake also had the Cadet 3 on display. She told us just what the pros on this site have been warning about: the toilets sent to the box stores are factory seconds or worse. The Cadet 3 in the plumbing supply house was "completely different" than those in the box stores, implying better quality. (The display model looked perfect to me too). But after a bad experience with a certain brand or model of anything (auto, washing machine, etc.) there is no room for a second chance.
From a CONSUMER: My advice is to spend the extra money and buy the Eco Drake.
Respectfully submitted,
achutch