You might want to measure driver speed as well. Would make it more interesting. I recall seeing Yodasluke swinging (or rather hitting) a dowel by a swing speed radar. He got it to 144 mph or something like that. 10's of mph's faster than the driver.
Also there are two SpeedStiks. As I recall you should use the red one if your body mass is over 160 pounds.
Again: Just a comment.
I'm not sure what the Speed Stik weighs, it might even be more than a driver. It's longer for sure. No comparison to a dowel.
The red weighs more than the blue. At 185lbs, I'm using the red one.
* I have no financial interest in this product, nor do I know anyone that does.