I've got the Delta and my biggest problem with it is getting
the feed belt to track properly.

The major issue for me was the drum support structure.
The Delta has the drum fixed and the table moves up and
down. On the Performax, the drum moves up and down
and the table stays fixed. But the moving table allows
for support at all four corners. The movable Performax
head however is supported only on one end AND has to
also MOVE. Seems the Delta arrangement can have more
rigidity.

Another consideration is the method of attaching the
ends of the sand paper (it's actually cloth backed) to
the drum. The Delta has a spring loaded clothes pin
type clip on both ends. Slip one end down into the
clip and it holds. On the other end you have to push
to open the clip to slide the end of the paper in. You
can rewrap the Delta by yourself. And it's fairly
quick and easy to d.

As I recall, the Performax was not as simple and may
require a tool and maybe an extra set of hands. So
ease of replacing the sanding strip can be significant.
At the first sign of clogging, if it's relatively easy to
do, you'll replace the strip BEFORE it starts to
burn your stock. If on the other hand, replacing
the strip is a PITA, you'll be tempted to keep the
clogged strip in use and deal with the resulting
burning later some other way. Unfortunately, the
burning may penetrate into the surface and tough
to get rid of.

Just more things for you to consider.

charlie b