Travelling in the USA at the moment and the toilets over here are different from those in the UK but reasonably consistent.
Firstly they are a much shallower pan than the average UK bog, and secondly they are generally viciously siphonic.
In general terms I think I prefer them. Any delicate souls should look away now :-) . . . . . . . Firstly the broad shallow pan eliminates the "long drop" of the average UK pan and also avoids the large splash you tend to get when you deposit something impressive. The only down side is the habit of something floating into view between your legs as you sit there contemplating life.
Secondly, the extra water held in the pan assists in the cleansing of the toilet bowl when you flush. This, coupled with the strong siphonic action, seems to generally clear the bowl effectively. However the siphonic flush is very aggressive - a fierce jet of water seems to be shot across the U bend which rips the contents of the pan away down the pipe work accompanied by a large roaring noise. This can be quite alarming where there is an automatic flush which attempts to detect when you have finished and avoid the necessity of you touching any handle or button. Especially alarming when you haven't even started ;-)
So why are toilets so different in the USA? I suspect that they use more water in the pan, and so may fall foul of some old water board regulation. I suspect that the syphonic part may use mains pressure water, again falling foul. However they do seem to be a better overall design than the UK ones in terms of efficiently removing crap.
The more mature and well travelled will probably also remember the French Colonial style of toilet which consists of a hole in the ground and a pair of porcelain footprints. These never seemed to catch on in the UK. They are probably also much better for you physically as they are closer to the natural way of doing things if you don't have modern plumbing. Less comfortable though, if you are catching up on the back issues of the Times.
So is there a good reason why our toilet pans are designed the way they are, and not like those in other countries, or is this just some kind of random variation?
Quite tempted by the US style toilet but I suspect that they wouldn't meet current UK regulations. I say this because I think they directly use mains pressure water and I seem to recall that this is banned (or was at one time) in most parts of the UK which insisted on cisterns to control water usage.
Amazing what your mind turns to late at night in a foreign country.
Cheers
Dave R