New ones should have the latest firmware, but if not, update it straight away. Don't want to make a cool patch and then have it sounding different 5 mins later.
Also, when using the cab models, use the high and low cuts. They are set to zero. They are the "secret" to a good amp sound. Set the low cut at about 75hz and the high at about 6khz. Stops the low end boom and any fizz.