First of all I want to start with saying that I am glad we got something. However, it is sadly not enough.
The goal was to make the S4 tier set an dps upgrade from our previous tier set, right? I think the changes failed to do that.
I only have 454 ilvl tier 3 pieces, but 519 and 509 ilvl tier 4 pieces. I still sim the same with my 454 ilvl pieces as I do with my 519 pieces. My manual tests on 5 dps dummies is also basically the same. It feels terrible! I prefer the playstyle of the S3 tier set, but I will of course use the S4 tier set because I can not play with the stamina I get from 454 ilvl gear.
I hope that your balancing team will consider another buff to the S4 tier set or just change it from S1 to S3 bonus. Our current iteration of survival hunter just plays better with the S3 bonus.
I think you can buff the M+ performance of the S4 tier set by increasing the proc rate and/or make the proc to not consume a Butchery charge.
Please also consider less focus cost in pvp. Should be the same as in pve now.