@RC556 I would spend a little more and get some nice Aadland covers. They will be much higher quality than the Butler Creek covers and will not break or slip off compared to the Vortex Defender or Butler Creek.
I agree with tenebraex, was not sure if they made them for the vortex so I didnt want to comment but its a toss up between tenebraex and Aadland on far as quality and features.
Depends on use. Mine sees the inside of the safe, to a padded case to the range and back. No need for expensive lens covers. Now, for a match gun, hunting gun, etc., it might be worth it.