I've used both the Panasonic SD-253 and the Breadman Ultimate. There
are pros and cons for both of them:

The Panasonic's bread-bucket is a seriously chunky piece of kit while
the Breadman's is much lighter, although perfectly acceptable. The
Panasonic's non-stick coating seems a little less robust although the
odd scratch doesn't make any difference. The Breadman's bucket is also
tightly retained by two spring catches while the Panasonic's can rotate
a bit too much for my liking.

The mixing on the Breadman isn't as good as on the Panasonic, in that
it is easier to get pockets of dry ingredients in the corners so it is
a good idea to ensure you have a wooden or plastic spatula around to
scrape round if necessary.

The Breadman is much more convenient to use - the window is very
useful, as are the Pause control, the one-hour power-loss memory and
the user-definable programs. I haven't ever got round to using the Jam
facility on the Breadman but I will at some stage.

In my experience, the results with the Breadman are somewhat better but
that may just be subjective!

All in all, I prefer the Breadman Ultimate to the Panasonic (despite
what Which? has to say about it) - it's more versatile, easier to use
and gives me more control.

The killer is that the Breadman is also cheaper - Robert Dyass are
selling them on ebay at £55 delivered (Salton is Russell-Hobbs over
here). I assume that the arrival of the new Breadman model is causing
the discounting of the current (to us) model but I also hear that the
new "whizz-bang" model isn't much of a real improvement.

As for the "lack" of a USB port, I can't honestly imagine why I would
want to bother with such a thing (and I'm a Computer Consultant and the
Ultimate Gadget Man according to my friends).