I agree with all you wrote about George, he´s my favorite sitcom character as well.
I also loved Jerry and Elaine, but I´ve never been able to actually relate to kramer.

If I had to pick one of the two shows, I think I´d pick “curb”.
I just love Larry´s character and almost all the stories have been awesome so far.
Watching Seinfeld, I usually didn´t like the kramer parts that much.
Another thing I like about Curb: it just seems to be a bit more “realistic” and lifelike, a bit less sitcom- like.
In Seinfeld, some characters definitely were kind of extreme and exaggerated (George´s parents, Kramer, Newman).
In Curb, the characters are more like people you could actually find in real life.

I also enjoy the fact, that the Curb humor is not just a “laugh out loud” kind of humor.
The jokes and the humor in general are evolving while the episode´s story proceeds.

The parts of Seinfeld I liked most, always were the George parts.
And curb focuses on these “George parts”. So I´d pick Curb .