Thread could probably use the some relevant stats for this year (everything from BBall-Ref, so I have no idea the veracity)
Walker - 75 games
25.2 ppg, 5.9 apg, 4.4 rpg, 1.3 spg, 0.4 bpg, 2.6 tpg
48.7 2PT%, 35.2 3PT%, 83.9 FT%, 55.1 TS%
111 ORTG, 113 DRTG, 6.3 WS, 3.1 BPM, 3.4 VORP, on/off per 100 +8.2
Irving - 63 games
23.9 ppg, 7.1 apg, 5.0 rpg, 1.6 spg, 0.5 bpg, 2.6 tpg
53.9 2PT%, 39.8 3PT%, 87.0 FT% 59.3 TS%
118 ORTG, 108 DRTG, 8.8 WS, 6.6 BPM, 4.6 VORP, on/off per 100 +2.5
In other words, Irving is generally better across the board. The only real arguments for Walker are better health and less drama, but that is it.