No down route aircraft swaps are not a problem if organised correctly and not done at the last minute like on my recent flight where all the bags were loaded and then decided to do the swap or like at my previous employer do an aircraft swap with an aircraft you know is running 1hr30mins late already.
I just like to read threads like this to see what's going on in the industry. I have to wonder: is this really something that people are looking at when considering a potential employer? I can't think of anything less relevant.