snap on prop guards v.s. stationary

[novice]

Does anyone know the weight of the standard prop guards v.s. the snap on/off prop guards ? I read that it cut down flying time 1.5 to 2 minutes. I have not been flying long and have read the pro's and con's of prop guards, don't won't to start that debate again. I only fly in open areas (park) and in my neighborhood in the street (not above houses). I was trying to practice longer distances and could not tell the orientation of the copter so the red front guards help me see better. I have since gotten the (shade) for my tablet helps a lot but don't like it !! also for a side note i landed once and I always use the downward motion to kill the rotors, once the copter just tilted over ??? would have surely crushed the blade! don't know what i did wrong but it's kind of a mute point (it happened) also when I'm at the Park uneven terrain I have practiced catching the copter. it has worked great so far !!