In terms of medals in global championships (outdoor) Cheruiyot has one gold and two silvers, while Kerr has one gold, one silver and one bronze. (Cheruiyot also has two silvers from the Commonwealth Games, while Kerr has none so far). Kerr has two indoor WC gold medals in the 3000m. Cheruiyot has no indoor medals. I'm not even sure if he has ever raced indoor.
PB-wise, Kerr is slightly ahead. 3:27.79 vs 3:28.28. I have to say that I have NO doubt in my mind that Cheruiyot in his prime could've broken 3:28 by a comfortable margin, considering his 3:29.26 solo/front-run in Doha 2019, as well as two 3:28 races with atrociously bad pacing. Lausanne 2019 (3:28.77 with a 800m split of 1:49) and Monaco 2020 (3:28.45, going through 400m in 52.x and 800m in 1:51ish if I remember correctly)
Kerr has broken 3:30 five times, and 3:29 and 3:28 one time. Cheruiyot has broken 3:30 13 times, and 3:29 five times, but never gone sub-3:28. Kerr has broken 3:30 in four different seasons, while Cheruiyot has done it in eight different seasons.
If I've counted correctly, Cheruiyot has won 18 1500m DL races. Kerr has actually never won a 1500m DL race (he has two 2nd places, and one 3rd place) In the mile Cheruiyot has two victories and Kerr has one DL victory.
Cheruiyot was almost untouchable in the 2018-2021 era (except the Tokyo 2021 final ofc) From 2022 he has been more incosistent, but he has had a great race every once in a while.
In the 3000m/two mile Kerr is far ahead of Cheruiyot with his 8:00.67 record (and 7:30.14 split) vs Cheruiyot's 7:36.72. But in the 800m it's the other way around with Cheruiyot's 1:43.11 vs Kerr's 1:45.01.
In terms of global finals, Kerr has reached six finals between 2019 and 2025, while Cheruiyot has reached seven finals between 2015 and 2025
There are more things to take into account of course, but I feel like I've covered the most important ones.
It's a bit hard to decide. Kerr has a knack of really rise to the occasion in championships, and he has show range considering his two World Indoor Championships golds in the 3000m. But Cheruiyot has been way more consistent and dominating in his prime (as well as competing more frequently) I'm leaning toward Cheruiyot.