Not from last September, but my X purchased about 14 months ago is still at 100% capacity per both the built in monitor and coconut battery. Cycle count is 178. While it's apparently not as good as the 11 series, I'm quite impressed with my X's battery life. I'm not a heavy user and I could squeeze almost 3 days out of it if I had to although I do charge daily.
I'm not too impressed with whatever happened to the 6s that I was using prior: