This topic has been on my mind for quite awhile. We know that the goal for gear is to have 40-50% power influence over our characters. This would suggest that the power influence of other customization like skill trees (that were showed in last dev discussion afaik) and augments have the remaining percentages (that is 50-60%) -
if you want to know only my conclusion and not how i got there skip to the end after the quote
In the recent dev discussion we can see that the presented character had 134 available skill points to allocate - it is a strong possibility that it was increased so the character was "maxed out" even though in reality we could have a third of those points or more likely the same as the amount of levels. Also we know that there are going to be quite a lot of augments available - and it seems that those are going to have more impact than 1 skill point
What I am curious about is how many of those customization options are going to temper with the power level and how many are going to be pure utilities.
We could for imagination sake say that we will have only 50 skill points available - 1 skill point could in theory represent 1% dmg increase (with 0.1% difference) and it could increase linearly with the amount of skill points allocated. Also we can see that at least for now there are 9 passive/active/weapon skills. Also it is not unreasonable to say that there will be multiple compounding interactions between those. Even if in the skill tree were only 3 compounding effects (like bleeds increase the dmg of backstab by x%, backstab deals x% more dmg, backstab costs x% less resources).
So considering the above we could have sweaty theorycrafter get together all skill points allocated into those that have 1.1% power allocated evenly between the 3 compounding effects with 17 points into 2 of those and last with 16 points. This will give him three linear power increases of 18.7%, 18.7% and 17.6% which compound on each other to give total 65.69% power increase.
However if you allocate unevenly and unknowingly allocate into the average ones - not the better outliers then you could have three linear power increases of 10%, 10%, 30% for a total 57.3% power increase.
If we consider gear stat allocation to be within similar margins and roughly same difference in power between the average "good" and the best in 57.3% and 65.69% then the actual power difference of all customization with gear is between 147.43% (the average "good") and 174.53% (best).
So let's say the basic rogue-rogue class has base output of 100 then the average person is going to scale up to 247.43dps and the optimized person 274.53dps. This is of course under the assumption that both have the same amount of available customatization and the same quality gear.
This is a definition of a near-perfect balance (0.1% difference between options).
So let's say the balance misses a bit and even though the average power of skill points is still 1%, but the outliers rise are in the range of 0.3-1.7%. then by going the same route above you retain the average "good" with 57.3% power increase, but the best outlier spikes to 28.9%, 28.9% and 27.2% for the 3 compounding effects. Which is in total 111.34% power increase. Also if gear optimatization lies within the same margin you retain the average 147.43% power increase for the average "good" builds, but the best spike to 346.66%.
This would mean that while the average guy does 247.43dps the best build rises up to 446.66dps and that is considering that both have the same quality of gear and the same customization options. Also I have completely neglected the existence of augments. Which can only deepen the difference more
CONCLUSION
What I am concerned about is that with the gigantic amount of customization and exclusive gear quality we could very well see a fully optimized character able to dish out the same numbers as a full 8man group if he has all the available augments, the top quality gear and all they have is the average dungeon drops.
Do you have any points that might expect easier balance? Personally I see only the balance being harder and harder to achieve with every customization option they have announced.