Thanks for testing this.
Old 3DS game usually load at the same speed on both systems but by using NTR you can make New3DS the faster system.
Since New3DS is faster even without NTR it is pretty safe to assume that there will be no difference between running on New3DS with NTR and without.

Mario Party: The Top 100

The New 3DS lowers load times?

Shovel Knight

Super Smash Bros. for 3DS

Shantae and the Pirate's Curse

Paper Airplane Chase

Kirby Fighters Deluxe

Kirby: Planet Robobot

Super Dangerous Dungeons

Super Mario Maker for Nintendo 3DS

Mario Kart 8 Deluxe

Splatoon 2

CTGP 7

Mini Mario & Friends: amiibo Challenge

bac0n