I think peak d will and peak cp3 were neck and neck.
Just for fun a statistical comparison of their peak seasons roughly averaged out (I will be as objective as possible)
Dwill: 19 points on 47% from the field, 35% from three, 82% from the line, 52% Efg. 3.5 rebounds, 10.5 assists, 1.2 steals, 3.4 turnovers in 36 minutes per game. Used a 4 year peak from 07/08 - 10/11. Hard to really pick a peak between those seasons. D will had more more points per game in 10/11 but worse efficiency for example.
Cp3: 21.5 points on 49% from the field, 37% from 3, 86% from the line, 53% Efg. 4.5 rebounds, 11.5 assists, 2.7 steals, 2.7 turnovers in 38 minutes per game. Used a 2 year peak from 07/08 - 08/09. His peak was quite clear and easier to define.
I thought it would be closer than that but Chris Paul peak was better than Dwill in literally every statistical category here. (maybe Dwill had better advanced stats or something but I'm not going that deep)
Cp3 was younger at the time they were drafted and also had better collegiate stats (I remember coming to that conclusion prior to the draft when I poured over their stats when I was deciding who I wanted the jazz to pick and decided on Chris Paul). I think we fell in love with Deron Williams size and that is what made us choose him. And he was awesome for us. I had a little bit of buyers remorse from that draft but not much. This was truly one of those can't go wrong with either guy situations.
Paul obviously had the much better career overall with his longevity of course.