The March 2010 issue of JLC (http://www.jlconline.com/cgi-bin/jlconline.storefront/4b974b670e3ba7ce27170a32100a066b/Catalog/Archive2010March) has a great article on High-efficiency toilets. A California plumbing contracting business decided they had had enough problems with low water toilets and customer complaints. So they used the office toilet as a test bed - over a period of 3 years they installed 6 different toilet models that meet the new 1.28 Gal. per flush standard. This new standard with be phased into codes over the next few years - especially in water scarce areas.
The company lived with each toilet for six months with all the problems and opinions noted. I expect they had a questionnaire at hand so the tester had something to do while sitting on the throne. :D
Click the image below to find the hands down winner of the experiment.
(http://admin.totousa.com/Product%20Images/CST743E_main.jpg) (http://www.totousa.com/ProductDetail/tabid/75/Default.aspx?ProductId=5cccd5d4-9645-4281-988e-81ef70f0ac9f&SearchId=70307c47-df2d-4042-8a7d-51f32d6c3a9f)
Both Toto models were high rated - the Eco Drake, and the Eco Guinevere. Both are standard siphon (low noise) toilets that could be installed in any home. The other tested models from American Standard, Kohler and Caroma would clear the bowl of solids, but all had problems with "backwash, cleanliness and noise".
Click HERE (http://www.saveonfaucet.com/Eco_Drake_Elongated_Two_Piece_Toilet_1_28_GPF_CST744E-P2412.aspx) for sample prices (or search on: "toto e-max drake best price").
Also, don't forget this website
http://www.cwwa.ca/freepub_e.asp#MAP (http://www.cwwa.ca/freepub_e.asp#MAP)
There are D/L PDF's of more toilets models than I imagined ever existed. All with test flush results.