The majority of my dwarfies have been older adoption hams that have been brought back to shop or just never been sold. I think they settle in just fine. I have recently took on a syrian hammie my friend could no longer look after she is 1 year old, and I think she is still getting used to me even though with her old mummy she was such a cuddly hamster.
But with dwarfies I think they settle in just the same and get used to you just the same as younger hams would. Syrians maybe a bit more time for them to get used to everything if they are unsure etc.
