Yes indeed, the search function is your friend. I used a different set of phrases this time and found a few detailed threads on this - but from what I found there's a general consensus that "if it ain't broke don't fix it" - still, I'd like to have this information for reference. I'm not sure it's a job for a rank beginner like myself, but I do have a few machinists I know that I can badger if needed.
I'm still plodding my way through all the links that this thread has revealed, but I'm starting to feel that the SX3 is the one to choose between the X3/SX3 - even if I do move to CNC it after a bit of time with it.
Thanks again for the assistance.