The transition to Mac Pro is now complete...everything works SO much better on the Mac.
Have completed three projects so far, two for external clients and all proceeded like clockwork.
Even with the same amount of ram that I had before it is working perfectly and not just the Mac either.
On Windows, my Tascam 1884 was a bit "iffy" on start up....but no problems on the Mac.
Some of the success is down to doing some homework before installing anything, making sure I had the correct software versions for all peripherals.
Here is a photo of happy composer at work...photo copyright courtesy of Clare Hines.