Hey there, I will start by saying I am a StamNB main, who also plays other classes but stamblade is the one I played the most since 2014.
I am seeing widespread rumors and fearmongering by other stamina NBs that class is dead, useless and other BS. Well, lets have a detailed look at it and see if that's true at all.
Grim Focus Changes
Firstly, I will state that Minor Berserk does not give it's full 8% extra damage due to buff stacking works. It is more like 5.5% dmg increase on average.
8% stamina recovery loss = 71 stamina recovery(standard PvE build) to 121 stamina recovery(PvP build with buffed stamina recovery without it at 1982 value). Average - 96 stamina recovery
Loss - 5.5% damage+96 stamina recovery for 20 sec
Gain - Upto 15% mitigation for infinite duration that needs 5 LAs. 10 sec increase in duration.
PvP
For PvP, mitigation is king in any kind of build and the damage loss from Grim Focus is a good trade, given stamina NBs don't rely on the bow proc and can afford to hold it till it is absolutely needed to secure a kill. We can shuffle sets(unless we are already totally glass cannon to begin with)and maintain the same baseline damage. For example, my roller-cloaker medium bleedblade and my roller-cloaker standard 2h/bowblade both used one damage set, one defensive set and one utility/sustain set. Now I simply run two new damage sets and one utility set and have more damage, with slightly higher defense but lesser sustain.
For Brawler builds, the new Dark Cloak heals for 6% HP eight times ticking every 1 second. It also gives Minor Protection for the duration. In comparison, the old Dark Cloak healed for 9% Hp four times ticking every 0.9 sec. While the old Dark Cloak was bursty, it gave Minor Protection for just 3.6 secs, compared to the new one's 8. The old Dark Cloak could not be kept up permanently but the new one can be easily kept up at all times and stacking with the new mitigation can open up offensive windows for longer periods and stacks with Rally/Vigor for a good baseline self-HPS.
Moving onto Surprise Attack, loss of Major Fracture is definitely a nerf. We got Ambush with Minor Vulnerability with same damage increase though which affects everything including bleeds, unlike Major Fracture. But I know all builds don't have barspace for Ambush so also considering the Minor Berserk loss, taking it as a nerf on the whole.
However, prior to the change, many good StamNBs used Steel Tornado as spammable too. So, lets say, if StamNBs had another spammable that does twice the base damage of the old Steel Tornado at all times, instead of just execute, with similar range, lower cost and other utility, it would be a great spammable as well. Voila, there comes Power Extraction, the AoE skill with the highest raw damage. Also, BTW Power Extraction was a pretty good spammable even before Elsweyr. So if you use Power Extraction instead of Surprise Attack, the nerf does not affect you anyways.
Sure, if you approach the NB like before, it is probably harder. But, if you adapt and start anew, NB is better than ever.
Also, one thing, I have been hearing a lot nowadays is NB is pigeon-holed into Heavy Armor S&B/2H for success in PvP and can not rely on purely damage anymore. For that is certainly one way, I beg to differ. Here are some examples of what it can do. I will start with a roller-cloaker DW/2H medium build.
Roller-Cloaker Blade build no-CP damage stats Roller-Cloaker Blade build damage stats Medium high-sustain Brawler Blade with nearly capped resists damage stats
As you can see, you don't need Minor Berserk to deal crazy damage, you can use the mitigation to give you that offensive window to go all out.
Ganker builds
You can see the crazy damage I can push on a standard roller-cloaker NB which is not even close to glass cannon with fairly good resists and sustain investments. On a ganker build, you will still have access to Minor Berserk with Camouflaged Hunter. Few pure gank builds use Surprise Attack as part of the gank combo, it technically remains the same.
Invoke your expertise in anatomy and enemy behavior to detect stealthed and invisible enemies around you for 5 seconds. Exposed enemies cannot return to stealth or invisibility for 3 seconds While slotted you gain Major Savagery, increasing your Weapon Critical rating by 2191. You also gain Minor Berserk for 5 seconds after you deal Critical Damage from Sneak, increasing your damage done by 8% - Which class do you think can use this to its full extent? Virtually nobody apart from StamNB
PvE
For high-end group PvE, only thing that is nerfed is a slight drop in Minor Berserk uptime, which is made up by gain of DPS by the new Dark Shade. With the longer duration, we will get five bow procs per Relentless Focus cast, instead of three, decreasing a bit of micro-management. Sure, we now have to add another DoT on top of probably the hardest rotation in the game and getting five bow procs per cast needs flawless rotation, but should we manage it, we should hit numbers higher than earlier patch.
For those of us in low and mid-tier DPS ranges, the main reason we have lower DPS is bad weaving, micromanagement and holding the bow Proc without noticing when it procs. So, the longer duration of Relentless Focus will help us get three-four bow procs on average instead of just one or two which increases DPS more than Minor Berserk does. Should we fail to use the bow proc in time, the added mitigation should be active quite often and help us die less and in PvE, the bow proc is a full-heal. And as they say, dead DPS is zero DPS. Also the new Shade does more damage than Rending Slashes, has a longer duration and is visually easier to notice. So if we are not confident to drop Vigor, we should drop Rending Slashes, which will save us stamina as it uses Magicka, which combined with Reave on Incap Strike gives more sustain than 71 stamina recovery.
For vMA, replace Surprise Attack with Power Extraction on non final-boss rounds, replace Rending Slashes with Ambush(8% damage from Minor Vulnerability is more damage than Rending Slashes DoT), replace Vigor with Reaper's Mark, which gives Major Fracture, a burst heal when something dies with 5 seconds of Major Berserk, which you can have a very significant uptime of as you will be mowing things down all around with Power Extraction. This setup is stronger than StamNB vMA setup on prior patches and it is totally possible to survive with Siphoning Attacks heal, Bow proc burst heal, which actually works like a Burst Heal in PvE, Reaper's Mark burst heal and Killer's Blade heal.