I weighed the four prop guards - 38 grams or 1.3 oz.  Anyone know how much the added weight costs in battery runtime?  Are we talking minutes or just a few seconds?

JD

No scientific data here but the battery time reduction is very small.  I'm thinking <30 seconds.  There are so many other factors involved - your speed, wind, camera usage, etc.

Not sure, I don't have them.  

just keep in mind that the more weight that you add to the drone, it might effect the performance of the battery  

Not sure about that

I would think the aerodynamics is as much a factor as the weight. Just hovering, weight might be the primary. However in zooming along especially in sport mode or factoring in wind. What about the turbulence difference with the prop guards. I have not done specific tests nor the math to calculate this. Just an assumption and food for thought. I have noticed, what seems like an increase in sound when my prop guards are installed. That in itself would translate to greater inefficiency of airflow. Perhaps a test might be to put it in a controlled environment, with a steady amount of wind, flying while being timed. Do this with the guards on and also with them removed. Almost need a wind-tunnel for this, if accuracy is important.

My opinion:  Does it matter, indoors? Outdoors are guards not really recommendable, imho!