The audio tools that come with Vegas aren't spectacular. However, the software accepts VST effects.
There is no shortage of free, good quality effects that you can plug into Vegas. I have a "typical" chain of three effects that I load up above and beyond the default EQ -- a De-Ess plugin, a gate, and compressor. All three are available for free, legally, and can be used as plug-ins for Vegas by basically dumping them all in the same folder then pointing Vegas to that folder.
Out of the box, Vegas can leave a lot to be desired. There is a lot of good potential in its acceptance of plug-ins.