So was it worth it
Followed Steves instructions by the numbers in the video above and got reduced latency memory timings to stick and prove stable under stress testing
Old spec was 3200 CL16 Corsair Vengeance LPX finished up at a modded CL14 using the settings straight from the suggested Dram Calculator.
Result is a bit over a 3% improvement on PCmark as per below and a marginal improvement on 3D mark but it is heavily weighted on the GPU. I did try running the memory at a higher clock (3400) and slower calculated timings and it failed and reverted the BIOS back to the old one. It is possible with playing I guess to make this work but it pushed the latency back to 16 again.
Taking the 3+% gain and calling it done until I get to my 2400G build then there will be definite gains to be made as the RAM is shared for graphics duty.