o summarize, Symbol Type Viewer allows to :
download the symbols (pdb) very simply.
sail and visualize in a detailed way the types and their members in the form of tree structure
easily find the unused areas in the structures (padding). These areas are theoretically usable to put personal data there
translate the structures for the C Language (.h) and for IDA script (.idc) of DataRescue (http://www.datarescue.com/idabase/)
personalize the formatting: addition of suffix in the names of types, freeze the sizes of structures and members (the pointers become ULONG32 for a 32bit system and UINT64 for a 64bit system)
apply searchs of texts or regular expressions
do a batch processing by treating all modules met in a directory and its under-directories. For example: C:\Windows;)