The cheap cronygraph has worked for me for the last 3 years as well. Once I figured out how and when to use the thing, it gives me what I want to know, velocities and thas it. It'll let you know when you find a good spread, and a bad spread. Thats all I have ever wanted it to do, and it only cost me $70. Lots of people I hear have had problems, but I have not experienced any, as of yet anyways.