I got the 45-150 and very please with how sharp it is. On the plus side it is 52mm which allow me to use my Nikon 3T & 4T close up filters, works very well. For longer reach I also have the 100-300 with the lens collar from roesch-feinmechanik.de in Germany (very well made). I did several test shots (45-150 on a GX-1) against my Canon 100-400 on a 30D and as far as I can tell they are pretty much equal in initial appearance using LR4 shot Raw with no sharpening. It was not a scientific test, just a series of long shots of cars and their tags using a tripod with and without stabilization and in late afternoon light.