VueScan is an easy program to use, it is largely automatic, and its defaults are preset for the goal of achieving best results with the most accurate color. If it seems difficult to use, you're likely diddling too much, trust it more, try the defaults. All you really need to set is scan mode and perhaps film type, and it can do the rest. You can size the preview and histogram window as large as you like.
You may sometimes want to tweak Brightness to affect midrange brightness (VueScan Brightness works as a multiplier to Gamma, same as any histogram Midpoint control). But otherwise, the main tone setting you may want to change is the Color Balance. Depending on the image content, one of these may be better than the others.
White Balance adjusts the RGB settings to try to make the image look white, often very desirable. Auto Levels adjusts the RGB settings from the histogram maximum data values, which then map to white. If the scene lighting was sodium lamps or an orange sunset, Neutral probably works best. Images without neutral colors such as gray or white, perhaps images of all green foliage or flowers, may not like White Balance mode, but more nearly typical images (people and places) likely will love it. Then the Auto Black and White Points clip away the specified percentage of the total pixel values. VueScan's defaults clip minimally, if at all, to retain the full data, to NOT discard shadow detail, giving all the range that a negative can give, perhaps a flatter image than you are used to, but it's all there.
You can set the Auto Black and White Points for greater contrast by clipping more, say 0.5% at Black. My own preference is to use the defaults for its magic (good color balance), and tweak contrast later in Photoshop (retaining that data allows choices). For typical scenes, following up with Photoshop Auto Levels (0.5%) is often fantastic. That clipping often enhances image contrast and colors perfectly, but sometimes it's the wrong thing to do. It does discard some shadow detail that VueScan tried to retain.
I'm trying VueScan to see how it will work for scanning a large volume of negatives and prints. I'm outsourcing this work so I want something very simple.
I'm impressed so far. It's very fast and it's very simple. Much nicer workflow than flipping back and forth from TWAIN. It scans directly to the image. Lets me control file naming pretty well. Mac and OS X versions.
A few downsides:
1. In demo mode it watermarks all images. Annoying. I hate scanning for testing and scanning again later.
2. I don't see how to make it use the native TWAIN drivers (if I wanted to do that).
3. Doesn't use a standard windows help file.
4. Install puts it in c:/ drive root. Annoying. I moved it.
5. Had some problems. Apparently known conflicts with logitech mouse.