What is your experience for the most effective form of Choline?

I was taking CDP-Choline for years based on recommendations from reddit nootropics at the time. And when I read eggs were a great source for them, I started consuming 2 eggs a day on top of that. I started pruning back some of my supplements as I wasn't sure they were helping. Choline was one of them, including eggs, and I didn't notice any reduction in my cognition.

Then about a year and a half ago, I forgot the reason, I ordered Alpha-GPC along with other supplements I would buy. After a month or so I felt a noticeable difference. I was sharper. Recalls were better. Learning also improved. I am still taking it to this day. My dose is 300mg of it daily, though bottle says I should take 600mg per day. I am taking half dose just out of caution and to observe moderation.

(personal note: I am a middle-aged male with concussion history who takes nootropics to enhance my brain health.)