Today a install ie9/RC . This program work very well with all websites . The speed is also very good the only problem i found is that some websites have to be in the compatibilty view in order to work just like when Ie8 was in the Release Candidate. Do i think you should use this update since it's out of the test mode ? yes and no
yes because of the speed
yes you can make this update work just just like ie8
the only con is if you use a online website you need to make shure they will support ie9 soon .All in all this in a must have broswer .