Steeks are very useful, if you don't like seaming. You can just knit the entire sweater in the round, cut the steeks, do a 3-needle bind off for the shoulders, pick up stitches for the sleeves and neck, and not one seam. And, you don't have to do it with just Fair Isle, I do it with any allover pattern, color or not.
What's cool to me is the neck steek, it looks all pinched in until you cut it, and then voila, you have a nice neckline. I use steeks all the time for jackets/cardigans, because you have no seams, instead of 5 different pieces to sew together, you just cut some openings.
What's weird to me is that some people don't even secure before they cut, they trust the old Shetland Wool to hold itsself together, which it does, but I still wouldn't think of doing that.