Water use and toilets

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Some time ago I opened an topic (thread) about new washing machines not using enough water.
A few of the members from here complained the same about toilets. I'm not an expert in sanitary installations, but can this affect the toilet in a bad way? I know that modern flush toilets uses some kind of system where the "route" of the water get a little bit thiner and the end, so a kind of push system forms and this is why they can use less water.
In U.S.A. I know that you have sometimes an kind of flush and vacuum toilet. You pull a rod of the flusher, an valve opens, the water from the toilet gets out, and when the valve closes, the toilet is refilled with water. How common is this system?