If you can get those modules to 1600, it would probably be worth it at that level. That being said, if you have to loosen the timings too much, it may not be worth it. I'd recommend trying it, testing it and see if you have any headroom without any voltage increases. It'll be safer that way and if you get stable, then it's totally worth it. Use something like PCMark or Memtest to get some before and after benchmarks too. That'll help with deciding if the overclock was worth it.