Single versus double lense

[DroidHunter]

Is there any real preference here? I know some of it is just personal preference. I was curious if there was more of a tendency to build one way as opposed to the other based on comfort, fogging, etc. My understanding is that neither method is required for acceptance. 

[SCTrooper[TK]]

For the stunts, most use the single lense, like the originals.  Simple and works very well. I use a fan in warm weather to prevent fogging.

[The5thHorseman[501st]]

Also when using a single lense, it leaves the bottom corners open (the lense isn't flat against the helmet) which helps for air circulation

[DroidHunter]

I like the clean look of two lenses, but was planning to go with a single lense. The TK's I have squired for both had two separate lenses. Didn't want to do something that was perhaps outdated or considered inaccurate if I went with the single lense..