I'm not testing on the PTS myself, but just going to chime in on the math. I built myself a calculator to compare the "Mundus Power" equivalent of sets, based on the Mundus stone stat "conversion rates" (i.e. wep/spell dmg, stam/mag recovery, resistances, penetration, health, stam/mag, crit chance, crit dmg %, healing %, excluding The Steed). I understand that different stats scale differently on different classes/builds, but this is a way to obtain the baseline "power" of set bonuses, as long as they can be approximated into the stats given by Mundus Stones. Most sets seem to be balanced around providing an equivalent bonus of 2.89 Mundus stones worth of bonus stats.
Actually it seems like most flat-bonus sets are balanced very closely to 2.89 "Mundus Power". For example, Hunding's Rage = 2.89, Spriggan's Thorn = 2.88, Fortified Brass (current) = 2.88, Ancient Dragon Guard (>50% | <50% life) = 2.89 | 2.88.
Other proc-based sets seem to be balanced similarly. For example, Briarheart (no proc | proc | proc on cooldown, ignores healing) = 1.63 | 3.52 | 2.89, Warrior's Fury (no proc | full proc | avg proc ) = 1.62 | 4.14 | 2.88.
Then you have trade-off sets that provide you a bonus at a cost, these usually scale higher in "Mundus Power" but their trade-offs are usually mathematically intangible or hard to approximate. For example, New Moon Acolyte (normal | adjusted for 5% cost increase ~-175? recovery) = 3.65 | 2.91, Bone Pirate's Tatters (forced to use drinks) = 3.24, Shackle Breaker (value only 1 resource | value both resources) = 2.07 | 3.60, Strength of the Automaton (physical damage bonus doesn't apply to healing) = 3.31, Essence Thief (no proc | proc - regen & 10% dmg approximation at 600 wep dmg) = 1.62 | 7.42(!).
Now, Armor of Truth, which is somewhat similar to Stuhn's Favor, IMO is kind of a mix of a proc-based and trade-off set. The proc, obviously, is the off-balance proc, where trade off is that the cooldown for the set is very large, and you can't environmentally control when and where off-balanced enemies occur, within reason. Armor of Truth (no proc | proc | proc on cooldown) = 1.63 | 3.56 | 3.12. Proccing on cooldown for Armor of Truth is 17/22 seconds, due to 10 sec buff applied at beginning and end of 7 sec off-balance window, with 22 sec off-balance cooldown
Okay so, Stuhn's Favor (no proc | proc | proc on cooldown) = 1.62 | 6.48 | 3.17. Proccing on cooldown is based on bonus during 7 sec of 22 sec off-balance cooldown. Compared to Armor of Truth, the off proc conditions of these sets are basically equivalent. The on proc condition for Stuhn's is 82% greater than Truth, but its duration is 41%. The average condition, based on 7 sec of 22 sec, is more or less similar to Truth, and no greater than other "trade-off" sets. Also note, penetration doesn't scale healing like wep dmg does.
So mathematically, it checks out. But practically speaking, especially in PvP, you aren't in a DPS parse while comparing these sets. The reality is you will be getting this bonus after the first time you Dizzying Swing any enemy and for the following 7 seconds, at which you have vastly superior power, and as such, the fight won't last longer than those 7 seconds due to that. So you are getting a reliably massively powerful set bonus with the trade-off being if you stuck too much to seal the deal you are weak for the next 22 seconds unless you simply swap targets. Seems pretty powerful, but also niche/one-trick pony.
So I can't really comment on the set, as I haven't tested it myself but hopefully some math will shed some light on the set.
@wylievcOkay so, Stuhn's Favor (no proc | proc | proc on cooldown) = 1.62 | 6.48 | 3.17. Proccing on cooldown is based on bonus during 7 sec of 22 sec off-balance cooldown. Compared to Armor of Truth, the off proc conditions of these sets are basically equivalent. The on proc condition for Stuhn's is 82% greater than Truth, but its duration is 41%. The average condition, based on 7 sec of 22 sec, is more or less similar to Truth, and no greater than other "trade-off" sets. Also note, penetration doesn't scale healing like wep dmg does.
So mathematically, it checks out. But practically speaking, especially in PvP, you aren't in a DPS parse while comparing these sets. The reality is you will be getting this bonus after the first time you Dizzying Swing any enemy and for the following 7 seconds, at which you have vastly superior power, and as such, the fight won't last longer than those 7 seconds due to that. So you are getting a reliably massively powerful set bonus with the trade-off being if you suck too much to seal the deal in 7 seconds you are weak for the next 22 seconds unless you simply swap targets. Seems pretty powerful, but also niche/one-trick pony.
The proc isn't tied to your character - it's tied to a target. You can have 100% uptime on the 5 pc of Stuhn if you're rotating off balance on targets or finish off your first target and move on to the next..
so not only does it not make sense in the "it has average of X value over time like other sets, so it's fine" (because spikes of burst damage are more valuable for securing kills in this game than average damage), it doesn't actually have to lose THAT much value in practice.
The proc isn't tied to your character - it's tied to a target. You can have 100% uptime on the 5 pc of Stuhn if you're rotating off balance on targets or finish off your first target and move on to the next..
so not only does it not make sense in the "it has average of X value over time like other sets, so it's fine" (because spikes of burst damage are more valuable for securing kills in this game than average damage), it doesn't actually have to lose THAT much value in practice.
That is an extremely valid point. And should heavily be considered when balancing/reworking this set in the PTS cycles.