My opinion is that it's a little easier -in a way- to listen to Paul's solo stuff than John's. With John, it could be very dark, very raw, stripped-down or bare. He had strong opinions on matters that not everyone agreed with. He was angry, could be nasty in a few songs, and always confessional. He, of course, had some super fun and more "lightweight" stuff, but you have to dig in amongst the other stuff to find it. I consider stuff like "Tight A$" and the entire Rock and Roll album to be a really fun side to John. I think you have to somehow know a little about John's history to really understand where he is coming from in his songs to really get them. Not that that is bad. I personally didn't even know too much about him and adored his songs immediately, but that's just me.
Paul's music is pop. He has a great sense of melody, lyrics that may mean something or nothing at all- but who cares because the music is so catchy? I personally think Paul's stuff is easy on the ears and enjoyable, but after awhile I get tired of it. In his solo career, I really, truly tried to like any one of his albums all the way through but it's just not my thing.I don't care for his lyrics, I think the music is mice but nothing more, and his singing is great but doesn't help much when I don't care for the song.
George didn't have the most consistent solo career (can be said for all four), but he did have All Things Must Pass and that in itself, aside from a few other albums I like by him, is saying a lot. That album is beautiful. I put it up there with Plastic Ono Band , Imagine, and Walls and Bridges for me.
