Vortex Magnifier, can anyone offer a opinion?

[Ebola]

Has anyone had any experiece with the Vortex magnifier and can offer a opinion? Im thinking of picking up one for my sparc on my m4.

Also i got a noob question when it comes to magnifiers. If i got my optic doubler on my sparc for a 2 times magnification and put the magnifier on it which has 3 times magnification does that eqaul 6 times magnification all together? Im unsure wether i add the magnification together or multiply it.

 

[PerversPépère]

You'll get to a point where the exit pupil will be too small for comfortable viewing.
A doubler is the maximum.
PP.

 

[Nikon Travis M.]

Yes everything multiplies together as you suggest, but the major drawback is as you do that you need double the amount of light to see the same thing you would without it. This is fine at high noon on a sunny day, on a dreary fall day towards sun set it'll be like you left your caps on.