I have been wanting a dual-flush toilet for a long time in order to save water in drought-prone California.  However,  I needed one with the trip lever on the side because the toilet fits underneath a built-in shelf.  This is the only one I could find.  And I had to buy it online, sight unseen.  I am delighted, because it is an attractive and comfortable toilet.  It also flushes very effectively.  My toilet is cleaner than before and my water bill has already gone down.  
I am so glad there was an option as to which side of the toilet the lever would be on, because had I put it on the left side (when facing the toilet, which is typical), it would have been hard to see.  
I am also delighted that I chose the bidet toilet seat option, which allows me to save on toilet paper and be cleaner.  Even though I am a Rubenesque-plus woman, the small seat is actually more comfortable than larger seat toilets.