I've just checked my first Vuescan scans, and they were terrible too. You do get better at it as you work out what the various options do and settle on parameters that work for you. However... I've not been very happy with quite a few of my scans of my modern C41 films, so I get these processed and scanned by a lab. It's a bit odd really, as I scanned thousands of old negatives using the same scanner and Silverfast 6 SE, and they mostly look acceptable. Of course I can't compare the colours I get with the scene from 40 years ago!
Of course a lot of this comes down to how the orange mask is handled in the inversion process. If you really want to get this right, the generally accepted notion is to scan your negative as a positive (ie, pretend it's a transparency), unadjusted TIFFs, and pass that via Photoshop (or Elements) to Color Perfect. This has really good inversion capabilities with a huge database of films. However, it's a bit more expense and disk space and a much more complicated workflow, so I've very rarely actually done it.