If you'd have to choose I'd stick with the 1610 since it is the only one that has the option to operate it either manually or automatically. Makes sense, right? Performance and reliability wise there is no difference at all, the way the tonearm & mechanism is built is totally similar.
However, if you'd somehow just happen to prefer one color over the other, that would make a lot of sense too.
I must note that though in the US most seem to prefer the brownblackish color since it is "more rare", in Europe there tend to be more brownblackish ones than silver ones. Actually I do prefer the look of the silver above the somewhat dull, dreary and dirty-brownish black.
A big advantage of the silver finish is that it is much less susceptible for staining. I have seen many, many black finished SL-Q2's, Q3's, 1310MK2, 1610MK2's etc with stains from fingers / wear and spots from spilled liquid (needle cleaner, oil, acid, sneeze spray, whatever
). Mostly the stains are darker, sometimes lighter. With the silver ones I have hardly ever seen a stain, if ever!