I have the 4th-version 28/2.8 and I had a chance to use the new one for a day at a Leica event. The new one is very small and light, like the 4th-version of the 35 Summicron. I really liked it's ergonomics, and for a new Leica lens the price stands out. That kind of worries me because it's a wide-angle lens and an ASPH and comes in less than the lens it replaced was selling for before all the huge price increases. I admit though there's nothing I could see from outside the lens that looks like a costcutting measure. Performance of the lens in my less-than-scientific approach: like every other Leica lens and most of the better lenses from other brands I've used, it's a satisfactory performer in real-world photography. Shooting bookcases from tripods isn't my thing, there are plenty of guys doing that, if that's what you base decisions on. If I didn't already have the 4th-version, which I paid $600 for because there's a tiny, barely-perceptible coating mark on the front, I would probably go for the new ASPH over the older version, if only because it's 2/3 the size and weight.