So, now that the Cyd vest is finished I've cast on for the Deep V argyle vest. It took a few gauge swatches before I figured out which size and needles to do/use, I also changed colours during the swatching stage as initially I was going to use a lighter grey, which didn't end up having any contrast with the green. And then a couple of re-starts while I did the usual messing up and miss-counting, and then another restart to switch to smaller needles for the rib. I'm now away from the starting gates and am pleased with the decisions I've made about size, needles etc.
My gauge isn't spot on, but is close. I think width-wise will be fine, especially once it's blocked, but I need to have a think about length-wise and decide if I need to make any minor changes while I'm doing the armhole shaping. I'm at the end of my first skein of green and nearly at the end of chart A, so I guess now is a good time to figure that out.