right now im running 16gb of Samsung ddr4 2400 MHz 2x8 gb sticks with the cas latency at 17. I was thinking about buying memory with either cas at 16 or 15. will I really notice a big difference? or is it a waste of money? need advice.
No. You might see a couple percent if the RAM is running the same clock speed. I wouldn't spend MY money on that "upgrade".
would you upgrade to 32gb?
Not unless you have a specifc reason. Video editing? Maybe. Otherwise the CPU in a laptop will be a limiting factor. You apparently have $$$ burning a hole in your pocket. On a laptop, I would spend it on solid state disk space.