That's a very broad question.
In the most general terms, I like my body since it allows me to live and do things I like, like move around, eat, sleep, jerk off etc. There's nothing cripplingly wrong with it at this point, I'm not dying any time soon.
That said, it isn't without its problems. I'm fat, so it's not that attractive and there are knock on effects. I have a couple of problems with my joints which affect mobility, though not to a massive extent.
Would I trade up for a better model? Yes.