Main differences that I am aware of:
- The engines are the same but the Denal's HP is just de-tuned a little to give Escalade bragging rights for marketing purposes. Torque is the same. Denali engine can easily be tuned to bring it up to Escalade specs and beyond.
- Denali does not have air-conditioned seats, Escalade does.
- Denali does not have xenon headlights but they can be bought via the aftermarket inexpensively.
- Denali does not have LED tail lights but they can be bought via the aftermarket inexpensively.
- Escalade's dashboard is more upscale but not enough to really distinguish it from the Denali in my subjective opinion.
- Escalade warranty is superior.
Bottom line: Denali is the smart money choice, Escalade is the cost no object choice.