The only thing I see right off that Keller jig doesn't have is the variable spacing. That gives you a vast choice of design vs fixed. My PC jig does a good job but is limited to a max of 12" width which normally is fine until you start doing case furniture. I had thought about doing 2 boards to join together to get the 17.5" total width and then realized the nightmare it could be aligning all 4 sections to each other. That's taking the 2 narrower boards to get the 17.5" on both side/front and back parts, a total of 28 through dovetails. Which again is why I hesitate to try that by hand not having any experience doing so. If it were 2-3 dovetails per piece on a narrow board it might be far more doable for me at this point but still has plenty of room to mess up.
As for the complexity of the Leigh jig, at this point I have a hard time using some of my less used tools without a refresher of the manual. Looking at the PC 4216 last night I just noticed the right side of the guide plates have depth stops for 1/4", 3/8" & 1/2". I've always used the variable stop on the left side......but again the limit is a 12" wide board and fixed spaced joints. Not that you can't skip a joint but certainly not variable by any means.
