I'm currently enforcing the flawed S3 standby on my 9570. It's rather slow, and now sometimes will get stuck entering the sleep state... so why I still use it? Modern standby and all lighter modes will just drain your battery, it's pretty uselsss. S4 aka hibernate with 32GB of memory is no fun either, even with an NVMe SSD it can take a while.

Also, that Firmware (UEFI/BIOS) is painfully slow to boot, go check your "last BIOS time" in task manager. For me it takes at least 8s, sometimes even 10-12, which is about half the total time it takes to turn on the computer! My rather cheap Acer managed to keep it at around 2s, and S3 enter/resume was almost as fast as that flawed "modern standby" on the Dell. On the other hand it was more than half a kilo heavier (GTX1060), thicker, bigger, and only had a quad core 7700HQ. Still, all those really annoying flaws on my XPS make me want to go back sometimes :(

IMHO the Standby is so flawed, that I consider to RMA it, as there seems to be no real fix planned. What's your opinion on that, anyone switched already to an other device because of all the issues?

I love Dell.  It is always a circus with them and quite entertaining, unless you own their products.