Here is an attempt at some probabilistic analysis on OC vs THF.
LW is +5W/+1CM with 1/4 MS cool down reset every 3 sec. MS is +5W/+3CR and 1/2 reset on Cleave/GC/SC min 3sec.
Probabilistically: cool down for cleave/GC is 5sec. So 20 Cleaves and GC per minute. 40 Cleave/GC actions at 50% => 20 MS at 25% => 5 LW.
Hasted Greatsword is 99.12 swings/min.
If I guesstimate the C/GC/LW/MS animation cycle at .25sec per C/GC/LW/MS swing => 40+20+5 * .25 = 16.25 sec of cleave animation time per minute. So 99.12 / 60 * (60 - 16.25) = 72.28 hasted swings per minute.
On that basis we can break down the numbers for an eSOS: 2.5[W=2d6],18-20/x3 using Devastating Critical.
- DC+OC+noTHF - 1043.204,165.508,264.7816, 678.855
- DC+GTHF - 1065.045,149.78,284.918, 719.055
- DC+OC+GTHF - 1132.865,165.508,300.646, 761.044
The list above contains three numbers, and the fourth being dps. The dps is given [W] = 7, Seeker = 10 and DM = 120. DM being 10 (esos) + STR + Power Attack + etc.
Conclusion: GTHF is better than OC.
The three numbers are multiplers again [W], Seeker and DM. Basically "Damage Effect Multipler per Minute" for each damage effect type.
The analysis also ignores weapon procs - this probably a disadvantage to GTHF as effects like vicious proc on every glancing blow - but doesn't matter much to the conclusion.
See http://goo.gl/pRJ63 for the full breakdown. Make a copy and play around with the animation cycle timing. Also not too hard to change it too other THF weapons.
I'm not entire sure if I'm make any logic errors, math errors and game system errors. It would be helpful if people spot any problems.