I had to RMA my 5333 kits.....  so snagged a set of these 
F4-4800C20D-32GTEG 
popped them in the dark, set XMP profile and it fired right up perfectly.  

rblaes_99
I had to RMA my 5333 kits.....  so snagged a set of these 
F4-4800C20D-32GTEG
 
popped them in the dark, set XMP profile and it fired right up perfectly.  

I just sent back the same 5333 kit, but I ordered F4-4800C20D-32GTRG

Gskill RMA'd all 4 sticks of the 5333 stuff no questions asked.  I actually sent two sticks to Nereus who had a FTW and DARK (like me) and he had the same exact issues.  would only run at JDEC 2133 speeds.....
 
GSKILL knew they sent junk out on the first batch for sure!

rblaes_99
Gskill RMA'd all 4 sticks of the 5333 stuff no questions asked.  I actually sent two sticks to Nereus who had a FTW and DARK (like me) and he had the same exact issues.  would only run at JDEC 2133 speeds.....
 
GSKILL knew they sent junk out on the first batch for sure!

Not necessarily, that they sent junk, but being thats a really high speed set of sticks they probably knew that they would be problematic way sooner than normal, would be my guess. Why send junk out if you know its coming back and gonna cost you more money? AND p-off your consumer? G-skills customer service is very good though, so thats no surprise there.

 
My Corsair Dominator Platinum 4000GHz ram (2x16BG) wont post on XMP settings on the Z590 Dark. This is the same ram I've had for a while that had zero issues posting on the Z490 Dark and an ASUS Z390 prior to that. Tried bumping the voltage up, tried putting the timings on auto and just setting the clock at 4000MHz, but nope, reset cmos required every time. I finally got them to post at 3600MHz with everything else on auto. I'm still trying a few things, I'll try gear 2 again, but this is getting really frustrating, and this is after having to return some 5333MHz memory that would not post over 2133MHz as rblaes_99 posted above. Kind of wish we could just disable this gear setting and go back to how it worked previously. BIOS 1.04.
 

i hate this gear business with the ram.  I also hate EVGA not publishing a QVL for RAM.  I have 10 sticks of premium DDR4 (tagged as compatible with Z590) sitting here and this is getting crazy. 

Luckily the board is new so bios updates could come out fairly often. I would contact support if you run into any RAM issues since they could be fixed.

 
Hope so..
 

The two kits I have and tested with the Z590 FTW are..

KIT 1:

Thermaltake XG 4400Mhz / PN: R016D408GX2-4400C19A
 
Modules: Hynix DJR
 
Tested with 4 Sticks, XMP Fails to boot and only boots if I change the XMP speed to 3600Mhz. Anything over 3600Mhz is a no go.

KIT 2:

Patriot Viper RGB 4133Mhz / PN: PE000585-PVR416G413C9K 
 
Modules: Samsung B-Die 
 
Tested with 4 Sticks, XMP loads successfully on both profiles.
 
Profile 1: 4133Mhz & Profile 2: 4000Mhz. No BSODs or crashes as of yet. 

PC Specs:

BIOS Version: 1.06

CPU: 10900KF

GPU: 2080 Ti XC ULTRA

RealKVX
The two kits I have and tested with the Z590 FTW are..
*snip*

Good idea, very helpful for people considering their options. Here's mine so far, I have more on the way from Newegg. Z590 Dark, BIOS 1.04, i9-11900K, 3090 FTW3 Ultra, all water cooled.
 
 
Corsair Dominator Platinum RGB 4000MHz 2x16GB,
P/N: CMT32GX4M2K4000C19
Modules: Samsung B-Die
Tested with 2 sticks in Z590 Dark, XMP Fails to boot in Gear 2 (or Gear 1) and only boots if clock dropped to 3600Mhz (is ok on Gear 1 @ 3600MHz). Anything over 3600Mhz is a no go, despite multiple attempts with raised voltage, VCCIO_Aux, and checked VSA was between 1.25 and 1.3V. The same set of ram had no problem working at XMP on EVGA Z490 Dark KP.
 
 
G.Skill Trident Z Royal Elite 5333MHz 2x8GB
P/N: F4-5333C22D-16GTEG
Modules: unsure, already returned. rblaes_99 might know.
Tested with 2 sticks on Z590 Dark. Could not post at all above 2133MHz... rblaes_99 has sent this set and his set back under RMA.
 
 
G.Skill Trident Z Royal Elite 4800MHz 2x16GB
P/N: F4-4800C20D-32GTES
Modules: Hynix
Tested with 2 sticks on Z590 Dark. Loaded XMP defaults and Gear 2, saved and rebooted, posted no problem at all. Thanks rblaes_99 for the help.
 
 
..currently waiting on some G.Skill Trident Z Royal Elite 4800MHz 2x16GB, p/n F4-4800C20D-32GTES. rblaes_99 already has this model and has been able to post at XMP settings (Gear 2) without issue on the Z590 Dark.