Main problem is when I nudge-tilt to line up vertically with helipad it drops suddenly from like 0-3 and it is difficult to have eyes glued to the gauge while watching where I am going.
I've had more the opposite experience with physics glitches. I can be flying along smoothly and suddenly the rope breaks or the heli suddenly flips upside down for no apparent reason or the cargo bounces up and destroys it. Not sure whether this is a bug or net desync. The Stomper is particularly prone to breaking off.
So YAAB is still a good indicator of your hardware performance, but you just need to concider that in MP, past a certain level of hardware performance, thanks to Arma's netcode, there will be no further benefits.
Tested today in multiplayer
my 4790K 4.8/4.4 GHz core/cache + 32 GB 2400 MHz DDR3
vs. 9700K 5.1/4.8 GHz core/cache +32 GB 4000 MHz DDR4
Results were same (+- 2-3 FPS difference, when view distance was 500-1500m).
So the higher the view distance, the lesser FPS difference between newer and older CPUs. Same goes for the GPUs.
The only scenario, where a more powerful CPU/GPU can make a visually unnoticeable, but still possible to measure (for the record) difference is between 500-1500m view distance.
So really not worth to OC your Intel CPUs higher than 5.0/4.7 GHz core/cache.
Also 4000 MHz RAM vs. 3200 MHz (XMP) made less than 5 FPS difference.
We both have same Windows version and SSD model and only Arma, Steam, Discord, Samsung Magician and MSI Afterburner were running on our computers.
GPUs weren't helping/hindering none of us, since we've done the tests in 1080p standard and 1080p low + everything possible disabled.
Server FPS was same all the time (almost 50 FPS) + hundreds of AI infantry + not more than 15 armored vehicles and not more than 10 jets/helis.
We were always looking at same spot, had same resolution and graphics settings and view distance (tried 500-7000m).
PvE server was full and we tested FPS as infantry at base, in Pirgos and Kavala, with 500-1500m.
And also hoovering 4 kms away from Pirgos and Kavala in the heli at 500m altitude, looking at these 2 villages with 7000m view distance.
So in MP, in Arma, you're not limited by server hardware, when server already always runs at max possible FPS (default 50 FPS).
But FPS you experience is limited by network traffic and Arma's netcode.
Even if the server would have been something like a new R9 5900X, instead of OC'ed i7-3930K, since FPS is already now almost 50, server FPS would have remained same, hitting 50 FPS limit.
And I doubt that with more recent/powerful hardware, there would have been less/more network traffic.
So what data gets requested/received by the server from what number of clients and what's synchronized to what number of clients is what dictates the client FPS, provided client already has a very good hardware basis.
So past certain client hardware performance level, there is 0 performance increase in MP, in Arma.