How slow is slow for how big?
I have maps with a dozen sheets, more than 700 nodes, lots of notes in
the nodes but no embedded documents or pictures that save in 3 seconds
on a 1.7 Ghz Centrino process with 2GB RAM. That is slower than some
tools on my machine but not the slowest. XMind save does not seem fast
but I am not sure I would call it really slow.