I wanted to know how much benefit swapping attunements really gives to Elementalist DPS, and how much of the benefit is utility.
Method:
Set traits to 0, unequip all gear except the relevant weapon(s). Record the (tooltip) damage and cooldown of all weapon skills. Calculate optimal damage rotation (via graphical optimization) in fire only over 60 seconds based on cast-time and cooldown information. Divide total damage by 60 to get DPS. Repeat for stance dancing rotation. Repeat for stance dancing rotation with 9s element return cooldown instead of 15s. Calculate DPS percent differences. Repeat for all weapon sets (Dagger/Dagger, Dagger/Focus, Scepter/Dagger, Scepter/Focus, Staff, Trident.)
Currently I only have data for Scepter/Dagger (it’s a lot of work.)
Fire attunement only: 802 DPS
Stance dancing, 15s return timer: 811 DPS
1.1% difference between fire only and stance dancing.
Stance dancing, 9s return timer (30 points in arcane): 910 DPS
13% difference between fire only and stance dancing.
Stance dancing, return timer removed: 1024 DPS
24% difference between fire only and stance dancing with the return timer removed, 12% difference between stance dancing with the 9s timer and no timer.
Sources of error:
Most trait lines currently provide significant benefits for staying in one attunement. Not having traits thus benefits stance dancing.
Cast times are not explicitly listed. I timed with a stopwatch and rounded to the nearest half second. Most (but not all) casts take about 1s.
I assume you can swap from one element to another and cast a skill instantly, with no delay. This benefits stance dancing.
I assume all skills hit, and all do their total damage instantly, possibly after a delay (eg Dragon’s Tooth drops after 2s, so if vulnerability runs out before it would do damage but after the cast I don’t add vulnerability.) Since conditions are currently stacking capped this provides benefits to Earth’s bleeds that are unlikely to be realized in a fight with another condition user who can afford to stack pure condition damage. Not counting this benefits stance dancing.
In addition, power and condition damage are additive stats, and gearing for a mix tends to be worse than focusing on one (or better, power + precision/crit damage, which are multiplicative stats.) Stance dancers do much of their damage from a combination of direct attacks and conditions, and thus have worse itemization. Not counting this benefits stance dancing.
Several sigils provide benefits when you “swap to this weapon in combat” which works on attunement swap. These may benefit stance dancers.
A 1.1% difference is not terribly significant, especially due to the increased effort required. A 13% difference is significant, but requires a heavy investment into Arcane traits. This would likely be offset by the reduced points in other trait lines (most non-staff builds take at most 10 points in Arcane, adding, say, 20 points in Air would give ~10% crit chance and +20% crit damage) In addition, almost all of my assumptions were made to benefit the stance dancers. The real DPS benefit is almost certainly lower, possibly even in favor of the non-dancer.
TL;DR: Swapping attunements provides a slight DPS benefit at best, possibly a detriment, and should be used primarily for utility. This seems to stem from the lack of synergy between trait lines and the presence of the timer to return to a previous attunement. Removing the timer to swap back to a previous attunement would increase DPS by up to about 12% for a stance dancer and up to 25% for someone converting from staying in one attunement to stance dancing.