For 2023 model: (didn't check 2022 R)
Denali Ultimate is now a trim level (vs an option package, like it used to be)
'23 Denali Ultimate interior is different from '23 Denali
AT4X is different from AT4
Each of the top 4 sierras have different interior colours
AT4 has 'Perforated Front Leather seating surfaces'
Denali has 'Forge Perforated Leather seating surfaces'
Both AT4X and Denali Ultimate have 'Full Grain Leather Seats'
LTZ has Perforated Leather-appointed front seats
HC has Perforated Leather seating surfaces
AT4X and Denali Ultimate have
A2X Seat adjuster, driver 16-way power including lumbar and massage
A7K Seat adjuster, passenger 16-way power including lumbar and massage
No 16 way on Silverado
AT4 and Denali (and SLT) have
A2X Seat adjuster, driver 10-way power including lumbar
A7K Seat adjuster, passenger 10-way power including lumbar
High trim Silverdo have these
AT4 and Denali (and high trim Silverado)
UQA Bose Sound System, premium 7-speaker system with Richbass woofer
AT4X and Denali Ultimate
UQS Bose Premium Series with 12-speaker system with CenterPoint, Richbass woofer and AudioPilot
Not available on Silverado
HUD
UV6 Multicolor 15" Diagonal Head-Up Display
Included on AT4X and Denali Ultimate
On AT4 and Denali - Included and only available with (CWM) Technology Package.
Similar differences on the high trim silverado