Strictly speaking, on offense, it's very close between them. Keep in mind Arron had a career year.
Pull Up Jumpshots
Waiters
FGM/FGA: 2.2 / 5.6 (38.9%) -5.0%
3PA/3PM: 0.3 / 1.0 (26%) -14.0%
EFG%: 41.3% -5.8%
Afflalo
FGM/FGA: 2.2 / 5.1 (43.9%) +5.0%
3PA/3PM: 0.3 / 0.8 (40%) +14%
EFG%: 47.1% +5.8%
Catch and Shoot
Waiters
FGM/FGA: 1.4 / 3.4 (41.9%) -2.7%
3PA/3PM: 1.0 / 2.5 (41.6%) -1.8%
EFG%: 57.2% -0.5%
Catch and Shoot PPG: 3.9 -2.2
Afflalo
FGM/FGA: 2.4 / 5.3 (44.6%) +2.7%
3PA/3PM: 1.4 / 3.2 (43.4%) +1.8%
EFG%: 57.7% +0.5%
Catch and Shoot PPG: 6.1 +2.2
Drives (Fast Break drives DON'T count)
Waiters
FG%: 40.6% -0.2%
Total Drives: 508 +293
Total Points: 276 +133
Drives per game: 7.3 +4.4
Drive PPG: 3.9 +1.9
Team PPG from Drives: 7.2 +3.6
Afflalo
FG%: 40.8% +0.2%
Total Drives: 215 -293
Total Points: 143 -133
Drives per game: 2.9 -4.4
Drive PPG: 2.0 -1.9
Team PPG from Drives: 3.6-3.6
Passing
Waiters
APG: 3.0 -0.4
Passes Per Game: 28.3 -11.2
FT Assists Per Game: 0.3 +0.1
Secondary Assists Per Game: 0.7 +/- 0
Assist Opportunities Per Game: 5.8 -1.5
Points Created by Assist: 7.3 -0.7
Per 48 Points Created by Assist: 11.7 +0.8
Afflalo
APG: 3.4 +0.4
Passes Per Game: 39.5 +11.2
FT Assists Per Game: 0.2 -0.1
Secondary Assists Per Game: 0.7 +/- 0
Assist Opportunities Per Game: 7.3 +1.5
Points Created by Assist: 8.0 +0.7
Per 48 Points Created by Assist: 10.9 -0.8
Touches
Waiters
Minutes Per Game: 29.9 minutes -5.2
Touches Per Game: 47.8 -10.3
Time of Possession Per Game: 2.8 minutes +0.5
Points per Touch: 0.33 +0.2
Points per Half-Court Touch: 0.36 -0.2
Afflalo
Minutes Per Game: 35.1 minutes +5.2
Touches Per Game: 58.1 +10.3
Time of Possession Per Game: 2.3 minutes -0.5
Points per Touch: 0.31 -0.2
Points per Half-Court Touch: 0.38 +0.2
Now granted, this is from a strictly statistical analysis. I freely admit that I have not seen Afflalo play very much. Again, this does not take into account defense, which I do believe Arron has the advantage. He has the height, the IQ, the rebounding advantage. But I don't believe Dion to be a bad defender. Over the course of the season, it seemed as if he was playing more hard-nosed D and not messing up his rotations as much as the beginning of the year. As far as Free Throws, Dion absolutely has to improve. He does drive more than Afflalo, a lot more, so as long as he increases his percentages, he should be just as valuable for that aspect. Yes, Arron is the better offensive player right now, though it's a lot closer than you would seem to think.
Also, remember, Waiters improved after the AllStar Break (I understand he was playing more minutes too).
Pre All-Star :
28.4 MPG, 14.3 PPG, 2.9 RPG, 2.7 APG, 0.2 BPG, 0.9 SPG, 41.7 FG%, 36.1 3P%, 67.1 FT%, 2.2 TPG
Post All-Star :
32.2 MPG (+3.8), 19.3 PPG (+5), 2.6 RPG (-0.3), 3.7 APG (+1.0), 0.4 BPG (+0.2), 1.0 SPG (+0.1), 46.0 FG% (+4.3%), 37.9 3P% (+1.8%), 71.4 FT% (+4.3%), 2.1 TPG (-0.1)
While Afflalo declined.
Pre All-Star:
36.5 MPG, 19.4 PPG, 4.1 RPG, 3.7 APG, 0.0 BPG, 0.6 SPG, 46.3 FG%, 42.5 3P%, 82 FT%, 2.1 TPG
Post All-Star :
31.6 MPG (-4.9), 15.7 PPG (-3.7), 2.4 RPG (-1.7), 2.8 APG (-0.9), 0.0 BPG, 0.2 SPG (-0.4), 44.9% FG% (-1.4%), 43.2 3P% (+0.7%), 80.2% (-1.8%), 1.8 TPG (-0.3)
So, when I take everything into account (age, contracts, stats, what I've seen with Dion), I would rather keep Waiters, but I do like Afflalo. He is more mature and experienced, that's for sure.