I heard from a friend that the XTS3000 won't do a Harris system that has their default settings with a XTS3000, as the base frequency for the Harris system is off from the Motorola by 12.5 KHz. Motorola won't do anything special to change the abilities in the ASTRO line to make it so you can change that setting, and short of changing the settings in the Harris system, there's nothing you can do. You have to move up to the ASTRO25 line to be able to operate on the system.
The only freq band an XTS3000, Astro Saber or Astro Spectra will ever do 9600 baud on is a 800 MHZ. While a UHF or VHF can be tricked into having the 9600 flash and firmware the structure was never in place to support it in the CPS and and firmware.