Which speaker has the biggest sound stage?

I tried out a Magnepan 1.7 a couple months ago, and I am a bit shock by the sound stage of it. It just feel live music. Although the bass is a bit lacking, I really like the "be there" feeling.

So, my question is, does all planar speaker (electrostatic, ribbon ... ) have such big sound stage? And with different brands and models, which one has biggest sound stage?

Specifically for Magnepan, the 3.6 is about $1000 more than 1.6. What are the major differences? and is it worth the extra money?