Re. Tippett: in general I agree. But I can take the symphonies: No.4 in particular made an impression on me from the moment I heard Solti conduct it. I'm not saying it's my favourite music, but I can certainly appreciate it. Which is more than I can say for Elliott Carter.
I'm in the middle of trying to come to grips with Maxwell Davies' 3rd. My goodness, that's a big beast. I'll let you know when I've come out the other side...