It's only slightly better than Code::Blocks.
IMHO C::B is better and it is getting better each day (just looks at the resolved fixed for the nightly builds)
. Anyway, I would not compare too much C::B with Visual Studio, because AFAIK C::B does not aim to be a new version of Visual Studio.
Code::Blocks only needs to fix the curent level of bugs, add some improvements already mentioned and add project dependency compilation and it would be on par with VS Express C++.
Which version are you using? Did you try the latest nightly build?
I've just created a project with VSE and it's code completition is on par with Code::Block's. Why is this a problem? Code::Blocks's code completition plugin has a *BUG* inside it while Microsoft's software AFAIK doesn't have a bug.
Code completion is WIP. Anyway, rikg22 has already implemented several improvements (see the nightly build of 11 January 2006).
Michael