I'm a "wider is better" kind of guy for this. A wide machine can surface narrow boards, but a narrow machine isn't going to help much with wide boards. Further, since you can "finesse" the cut with narrower stock, such as angling across the cutters, you can often surface highly figured boards with less tear-out. My J/P combo is 350mm wide (about 13.6") and it handle most tasks that I ask of it. There have been a few times, however, that I wished I had a couple more inches of width available!
BTW, I never use my jointer for edges...purely for flattening stock. Being blessed with a great table saw, once I have a flat board at a given thickness, my rips and crosscuts are perfectly perpendicular to the face(s) of the workpiece and don't need edge jointing.
Last edited by Jim Becker; 02-07-2013 at 5:28 PM.
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The most expensive tool is the one you buy "cheaply" and often...