The biggest factor to making performant, good looking terrains is to tune your data for the expected usage. The algorithm will deal well with almost any data set, but if you know how the landscape will be viewed, you can make some optimizations.

First, find the highest error metric that looks good. Pay attention to the polygon usage report from the chunk generator. You might need to up your error metric, or make the chunk quadtree deeper.

For texture quad trees, you need to find balance between depth of the tree and size of the textures. Larger textures will load more quickly, but may cause hitching when they upload. Smaller textures will load more smoothly but potentially take longer to detail in. Similarly, shallow trees load faster and take less memory. (The parent levels of a texture remain resident in memory while the child textures are loaded.) But deeper trees allow you to have more detail without having to increase your texture size. Node texture sizes over about 1024x1024 may run less well on older cards.

If you know that you're going to be up close to the terrain and moving relatively slowly (ie, an FPS), you can have a deeper, more detailed geometry data set. On the other hand, this is a waste for a flightsim - you can spend more resources on high texture detail, and cut back significantly on geometric detail.

Also be aware that the terrain collides exactly against whatever is rendered for the lowest level detail. Having too many polygons in a single chunk at the lowest level may cause some performance issues.