Often, vests like this are knit circularly from the bottom, then back and forth above the armholes.  That midstream change in method alters the lie of the stitches and can often make for noticeable inconsistencies in stitch direction and, occasionally, even gauge. Sometimes, folks steek the entire front and the armholes, then finish all those raw edges with cross stitches.  Steeking everything is definitely an improvement, but (yawn!) that's a whole lot of (usually messy) cross stitch you'll be, um, "facing". Certainly, there are some magnificent examples of vests worked this way.  However, I think I've improved upon these techniques by adding double pick-up facings to neatly capture those pesky raw edges. (See the pink bands on the 2 left-hand photos for the inside facings and notice the slightly raised effect on the fatigue green portion of the outsde facings.) As much as I love steeks, I hate weaving in.  In this design, the color changes are all done at the steeked front and the vast majority of your raw edges are tucked into the double facings so that there is almost no weaving in left to be done. Yeah!