Some obversations from Jerry Work, well known furniture maker, in a similar discussion a few years ago:
"One big feature [of a jointer/planer combo] is that you are jointing and planing with the same cutter head, so the joined side and the planed side will take finish the same way. For critical work, the different knives on a separate jointer and planer often will result in the finish winding up different on the joined side from what it is on the planed side. A second feature on the Felder and MiniMax versions of these machines is there is no snipe, none, nada, so you do not need to over cut your pieces before joining or planing.
But, for me, building fine furniture all day long every day, the most important benefit from the combination machines is that I walk far less than when I used separate machines. I simply do a dance moving between the various functions, first breaking down most solid woods to rough length, then to the jointer function where I joint one face and one edge, then to the band saw where I rip to rough width and thickness (way safer than ripping on a circular saw), back to the planer where I plane to exact width and thickness and then back to the saw function where I cut to exact length. In my studio set up this is a very tight, efficient circle. It is fast enough that I never both to cut more pieces than I need. If one piece turns out to be bad, I simply make another on the fly.
Since adding the Kapex work station to this set up I now do the initial solid wood plank break down to rough length on the Kapex and often return there for the final cuts to exact length as well. I have the Kapex right and left measured stops calibrated to the squaring fence stops on the sliding table so each produces the same result. If there are a lot of pieces to cut to exact length I use the combination machine as it is a bit faster to do the squaring cut on one end, flip the piece and do the dimension cut on the other there than it is to move the wood side to side to make both cuts on the Kapex."