rstroup: For a beginner, no. Not necessary at all on a 450 IMO. You can just run a proven motor+battery+pinion+blade combo that you know works, and also assume you get headspeed roughly the same to what others report with the same combo.

However, if you want to set up a Govenor mode on your ESC correctly, you MUST have a Tach to do it.

Also, if you start to do any competing, etc., you will certainly want to know exactly what your HS is for sure