Vectric VCarve is another very popular (albeit somewhat pricey) upgrade path. The name is slightly confusing, as it is not only specialized in V-carving but is a complete generic CAD/CAM tool. The workflow is quite similar to Carbide Create's, which makes the transition easy. It has more CAD features (layers, support for 2-sided machining,...), intermediate-level CAM features (built-in support for roughing and finishing strategy is great), and it is just a very polished and robust software. You can also go crazy and buy the top of the line Aspire software from Vectric, if you need the advanced/pro features it offers.