MI-L MapXtreme Java , 3.5 or 4.0?

[廖啟雯]

Hello, dear listers:
 
We are evaluating the possibility of purchasing MapInfo MapXtreme Java.
The situation is that version 3.5 is cheaper, while version 4.0 is much more
expensive.
Is there anybody having experiences on both versions?
What functions are added on version 4.0?  Are they important?
 
 
Hope to get some advices.
 
Thanks!
 
Keven