A nice ~3x reads improvment on Linux v6 
SN850 500GB, i5-1240P, btrfs (rw,noatime,compress=zstd:3,ssd,space_cache=v2,subvolid=5,subvol=/)
via fio and approximate CrystalDiskMark settings
Linux 5.19.11-arch1-1
Sequential Read: 1684MB/s IOPS=52
Sequential Write: 2580MB/s IOPS=80
512KB Read: 780MB/s IOPS=1560
512KB Write: 2133MB/s IOPS=4266
Sequential Q32T1 Read: 1600MB/s IOPS=1600
Sequential Q32T1 Write: 3636MB/s IOPS=3636
4KB Read: 62MB/s IOPS=15968
4KB Write: 299MB/s IOPS=76560
4KB Q32T1 Read: 930MB/s IOPS=238139
4KB Q32T1 Write: 528MB/s IOPS=135181
4KB Q8T8 Read: 2215MB/s IOPS=567172
4KB Q8T8 Write: 536MB/s IOPS=137239
Linux 6.0.0-1-mainline
Sequential Read: 3076MB/s IOPS=96
Sequential Write: 2807MB/s IOPS=87
512KB Read: 1428MB/s IOPS=2857
512KB Write: 2253MB/s IOPS=4507
Sequential Q32T1 Read: 3636MB/s IOPS=3636
Sequential Q32T1 Write: 3333MB/s IOPS=3333
4KB Read: 61MB/s IOPS=15796
4KB Write: 273MB/s IOPS=69897
4KB Q32T1 Read: 903MB/s IOPS=231412
4KB Q32T1 Write: 458MB/s IOPS=117363
4KB Q8T8 Read: 2179MB/s IOPS=557878
4KB Q8T8 Write: 532MB/s IOPS=136289
