IE9 is now available to download (technically Release Candidate - which is the final of the finals but  essentially the Real Deal).

One issue which may slow adoption is that it is limited to Vista, Windows 7 and Windows Server 2008.

Does it work for Audit Assistant? Yes - very well.

Should you change from Chrome? No. It's caught up to Chrome in speed but unless you are a committed Microsoft person there doesn't seem to be any compelling reason to change.