>>is there any specific usage of XSLT mapping in real time environment.
XSLT is more commonly used when you need to generate some complex structure,lets say you want the whole XML in a single tag on receiver side,then you can use CDATA in xslt and do the mapping.
Similarly depending upon other req. we select the best mapping technique
XSLT Mapping is used for various sorting.
when u think graphical mapping is very complex in ur scenario u can go for XSLT mapping.