Back to the purpose of the OP. I found the bike-fit section of their website reasonably accurate for me, although I seem to have fairly standard arm and leg length for my height. On the whole the frame letter size (S, M, L etc) goes large. I'm 6 foot and the Medium frame is a good fit.
If you're considering an Aeroad, remember that there's no adjustment to the integrated stem/bars and the position is
reasonably aggressive. You can swap them for a standard stem/bar combo, but it's extra money you don't need to spend. I found it more comfortable than I expected even for 5-6 hour rides, and I'm an old giffer.
I'd take the frame cracking issue with a pinch of salt. Most large manufacturers suffer this kind of story at one time or another (I think it was Cervelo last time). That said, Canyon have had their supply issues in the past (use search) although these seem to have been rectified to a point. I found them helpful when my Di2 battery developed a fault.
Off topic, but good to see another southern blue on CC. Dad from Wythenshawe, so I wasn't given the choice of team (he wanted to call me Colin Denis Bernhard ..... but my mum stepped in, so that gives you the idea
)