All toilets made today use 1.6 gallons per flush (or less). Not all company's toilets work well. You can't buy a new toilet that uses more...they just aren't sold here legally. The standard is likely to change to 1.2gpf in the coming years. I've heard good things about the double-cyclone flush on Toto's newer toilets. A popular one is the Drake II. High, consistent quality is a Toto trademark. The street prices are often much less than the suggested list price. They aren't sold in the big box stores, but most any plumbing supply can get them if they don't already have them. A toilet is often a once in 25-year or longer investment...a few bucks more (and not necessarily) is worth it for wear parts that are readily available, and one that works well out of the box.