Oh dear, oh dear. I'm only a lightweight AUK (rarely going over 200km) but Hummers's post on page one rang so many bells it's frightening! I suspect quite a few of us here were brought up short thinking yes, it's supposed to be a humerous post, but.....
There's no particular magic about an audax ride, or a sportive or a CTC reliability ride. Don't choose a ride for what it is, but because you want to do it. No point doing it if it's just to tick another box, because then there is a danger it becomes a chore. And then it won't be enjoyable.
As it happens, Kennet Valley Run was my first 200, back in 2003. Not a bad first 200. But Taste of the Test in May gives more daylight, and is a delightful route.