Last night, I sewed together the for sections of the sock for Piecework's upcoming Knitting Traditions special publication.
The seams involve working a whipstitch to join the bind-off edge of one piece to the cast-on edge of the next. Fortunately, each piece has the same number of stitches so the pieces are sewed together stitch for stitch and no easing is involved. I tried to sew fairly loosely to maintain the elasticity of the knitting, but the seams do make tight areas that are a little more difficult to pull over a heel.
I can convince myself that the seams make decorative design elements, but I can't say that the practicality of being able to replace the heel and toe are worth the fuss. I'd rather knit another pair of socks!