I've never done it down the center, so I can't compare the two as far as difficulty . The way that Brian Shultz show on his website looks pretty easy and quick. I start mine much the same as usual, stretching the skin along the keelson, except for leaving more skin on one side. I set push pins all along the keelson to keep it from pulling out of line, then flip the whole kayak over. on the seam side I pull the skin up using upholstery tongs and staple the skin to the top of the gunwale. Then trim the excess, I generally need a small dart in the cockpit. Then pull the long side over and do the same. I've used both straight and curved needle with 20# test braided line to sew the seam, removing the staples as I go. I keep my stitches pretty close, maybe 1/4" apart, so in that respect it probably takes a lot longer than using a whip stitch up the center. When I sew I fold the top under to get a hem, it ends up a nice clean looking seam.

Bill

: Bill, do you consider sewing along the gunwale easier or more
: difficult than sewing down the center of the deck? Are there any
: peculiar steps to doing it your way?