My last build had the NH-D15 and it was good at what it did. For this build i decided to go with my first AIO -X72 Kraken and i have been very happy with it. People knock the CAM software but i have had no issues with it at all. Right now 9700k is at idle at around 36-37c with a room temp of 24c. What i do love is how quiet the rig is now compared to when i had the D15. Temps dont really go above 75c for me with my i7 9700K at 5GHz when i am in MSFS so overall very happy. I did notice tonight that the 3090 runs a lot cooler than my 2080 RTX did. It would hit 82c in MSFS. Tonight the max temp recorded on the 3090 in MSFS was 67c so plenty of headroom with it. Think you will be happy with the Kraken if you do go for it.
Can see the X72 Kraken front mounted in my pic.