Just to add one more factor, what happens overtime in old toilets is that sediment stone develops on the inside, and causes enough friction for the toilet paper

Just to add one more factor, what happens overtime in old toilets is that sediment stone develops on the inside, and causes enough friction for the toilet paper to catch and plug up. So you can probably except even shorter life span from the new toilets as they flush less water, so more likely for that stone to develop. So you're more likely to need to replace the toilet in the future. Also the flushing mechanism is proprietary, so if anything goes bad, more likely to have to replace the toilet. Really debatable if having to replace toilets more often is environmentally friendly. It will make more money for the toilet manufactures.