18-55 to 18-105 is not an upgrade...neither sharpness,or built quality or even aperture. I got my 18-105mm because it's the best possible range for DX & I need it for street photography.
I never heard of people returning a lens for it's closest focusing distance...this is the 1st
a "all-around lens" will never focus close,that's logical. if you need a lens that focuses close,get the 35mm F/1.8
fast focus,compact,very nice build,amazing sharpness & F/1.8. if you care about focus distance,then you must be into portraits or macros. so that lens will be awesome for you,for endless applications