Which speaker has the biggest sound stage?

I heard a set of very large planar speakers, I think they were Magnepans but I am not sure at the CES in Chicago in 1989. That was one of my most fun days ever, seeing all the rooms in the hotel across the street set up with different stereo systems and people peddling their hifi wares. So these speakers were set up in the big Ball room. Four large panels powered by 4 large, separate ARC tube amps. A classical piece was playing and it was like a life size orchestra in the room. I could pinpoint every single instrument in the orchestra. A very memorable experience.

I myself had and enjoyed planar speakers for 14 years. It was the opposite for me. My wife liked how they looked and was upset with me when I sold them to try something new. I was always impressed with the speed and imaging of the Thiel speakers. I'm very happy with my Thiel speakers now and with analog especially, they can produce a large soundstage. The only downside was the expense to amplify them since they like lots of current. Planar speakers are much easier to drive being typically a resistive load.