One of the biggest problem with cylinder arm machines mounted on tables with cut outs under them is arm clearance. The pedestal stand cures some of those problems but!! First, I have never liked the metal pedestal stands that they mount so many machines on. The castors raise the machine up to high for it to be comfortable when using the foot pedals. Second, the pedestal arm is to far back on the stand. You are leaning over to sew things way more than you should. The pedestal should be 4" closer to the sewer on the base. Third, when they mount them, the base of the machine should come right up to the left edge of the table top. Otherwise, you loose arm space for sewing on the arm.
I mounted my DA669 on an off the arm table myself. Set it up like I wanted it. No complaints. With thing to note: With the machine mounted on an off the arm table, you may want to get a slide on flat table attachment for those items you will be sewing that need a table around the arm.