I purchased an Edge 3 this past summer. The transducers are difficult to mount and set up. I found I needed to play around with them a lot to find the balance between getting no rooster tail and good high speed performance. I ended up with a slight rooster tail on my Lund. Really no worse than I had with Lowrance.
I have them about 2 inches apart. Vexilar has a installation video on their website but I found some parts of the video deceiving, especially the downward angle on the rear of the transducer. The instructions say 2 to 5 degrees but if you were to follow the video, which I initially did, the angle is much steeper than that. After I foloowed the video, you needed a rainsuit at the back of my tiller boat from the rooster tail! Use the attached instruction as your guide, not the video. http://www.vexilar.com/pages/support/support_tips/article_002.html
The transducer mounting is more difficult than a Lowrance, but once done, the Edge 3 is simply fantastic, I couldn’t be happier with it!