Benfits of Outlook 2007 vs 2003? Is it worth the upgrade?

Hi,

I am currently an IE 6 user. I keep trying IE 7 & find its much slower.

I also am an Outlook 2003 user. I like it, its fast enough, works well with exchange, etc. I played with Outlook 2007 using Vista on my laptop (pentium M 2ghz, 1 gig ram, etc). The whole setup was extremely slow.

I ended up reinstalling XP/Outlook 2003 & all is speedy again.

Am I missing some great feature of Outlook 2007? Will it be faster/worth installing again?

I have an exchange account which gives a free copy of outlook 2007, so there is no cost to the upgrade (aside from the yearly exchange account).

Thanks,

Rich