What are some alternatives?
When comparing R2V and Wintopo, you can also consider the following products
CR8tracer - Convert bitmap images into monochrome vector formats
Ras2Vec - Raster to vector conversion program for Windows 95/98/NT
Autotracer.org - Free online image vectorizer
KVEC - Tool which can vectorize images using several graphic formats
Vector Magic - Easily convert JPG, PNG, BMP, GIF bitmap images to SVG, EPS, PDF, AI, DXF vector images with real full-color tracing, online or using the desktop app!
Super Vectorizer - Mac vector trace tool to convert raster png to SVG vector graphic.