I used to see a fair number of post on various forums about the 20/1.8, 24/1.8, and 28/1.8 and which of three was the best. They all get votes. Mine was slightly soft wide open but very sharp from 2.8 to f8 and I loved the close focus capability. I sold it because I used the 12-24 much more often and, frankly, think its better at 20mm than the 20/1.8. I also have the 28/1.8 which I like very much and can recommend highly. I can't speak to the 24/1.8 having never used it, but I suspect it's well worth the price.