Hi Dick,
Capture shop and Exposure software are free downloads from the sinar site....upgrades free as well !
I use mine for Architecture shooting and love it, files are clean plenty of latitude - without starting a war regarding DSLR's and how they compare... I use both and find the 54M files better than anything I have shot with even the D3X. It is however, MUCH more cumbersome - in my work it suits me fine as i am usually on location for the day, night or both ! lol
Specifically the back combined with the schnieder glass is far sharper than anything I have been able to produce with any dslr (as would be expected)
dynamic range is great and files hold up well if you need to do heavy manipulation.
I have also used it with a P2 and sliding back for stitched shots and it supports live focus with that rig
I know it is an older back but produces excellent images, I cant even imagine what the new backs are capable of !