I'm looking for a low-cost platform for playing with old legacy lenses. In my case, I have some old Nikon glass, which still mounts fine on my Nikon DSLR, but focusing is tough. Which of the sub-$1000 non-SLR interchangeable lens cameras is the best at manual focus? I've read articles about people using the discontinued NEX models for old lenses, but I have no idea how they compare to the competition. Are there differences in compatibility? Do any of them meter with manual lenses?