i'm in your conscience
I know I've played Platinum fully twice, and I'm on my third run currently. Diamond I've played once, because it's the same file from April 22, 2007 (US release date, if you didn't know!). Pearl, however, I lost count of. That's how I used to know the games so well, because I constantly replayed it lmao. Started my first challenge here using Pearl, so as much as I hate DP, I do owe it that credit. Platinum wasn't even around. Neither was the Challenge forum. YEAH. It was that long ago.
I would say it's less than RSE, BW, and FRLG, but probably even with HGSS (Johto part only).