The current version of Chrome is 5.0.375.99... Chrome Plus is at 5.0.375.38.

I'd be more worried about the vulnerabilities fixed in Chrome that aren't fixed in Chrome Plus:

http://googlechromereleases.blogspot.com/2010/06/stable-chan... http://googlechromereleases.blogspot.com/2010/06/stable-chan... http://googlechromereleases.blogspot.com/2010/05/stable-chan... http://googlechromereleases.blogspot.com/2010/07/stable-chan...