After making the changes for 40% SnD and the nerfed Muti / buffed HfB as illustrated earlier in this thread, I further modified cell C7 on all 3 DPS calculations to reflect 2% haste per point into lightning reflexes. Unsurprisingly, this shows that a 13/51/7 combat dagger spec dethrones 51/13/7 muti by over 1%. This is before the upcoming changes to Killing Spree (+20% dmg boost for 2.5 seconds), which would only broaden the margin between the two specs.
I was wondering if anyone else had played with the spreadsheet and has found similar results.
All the best,
EDIT: a 15/51/5 spec with 3/5 RA comes up as half a percent better than 13/51/7.