Thanks for your insightful answer, Jonathan!
Just to be clear, would I be correct in thinking that given that I have sufficient funds for either an Atlas OR an Olympos SL (but not both at this time), the Atlas would be the better option, even though I have a Parnassus I can use as a donor)?
Assuming the Atlas is the one to go for, I'll probably hang on to my Parnassus (even though the suspension has recently failed, hence why I'm in the market for a new cartridge). If the funds ever become available, I like the idea of owner an ultra-rare Olympos SL, and I'll need my Parnassus to make it happen! :-)