IIRC, the biggest jump in gaming framerates comes from 1600 to 1866 with smaller incremental jumps above that. Your best bang/buck is probably there, as the faster sticks get more expensive.
FWIW, on my Biostar board, my older 1600 sticks run stable at 1866, but the board really loosens the timings when set to auto for that speed. I could probably tighten them up and test for stability, or maybe up the voltage and try for 2133.
In any case, you probably won't notice with the applications you mention.