The purpose of VAST was to take advantage of vectorization on certain historical compilers by substituting array assignments for DO loops. In the cases where optimization is prevented by poor coding practices, VAST wouldn't have been capable of correcting it. At the time it was marketed, a few Fortran compilers depended on array syntax for optimization, while a majority performed better on f77 source code. You may still be able to download some examples of the conversions it performed. VAST wasn't a satisfactory tool to perform even 20% of the work of f90 conversion, so its price wasn't justified for most people.
The public tools perform fixed to free format conversion, and perhaps some cleanup of legacy DO loops, but don't apply array syntax conversions. So, you are unlikely to find a single tool which performs more than 50% even of the part of the conversion which ought to be practical to automate.
