So which is a better window? Marvin infinity, eclipse or soft-lite ? What about Atrium?
It depends on your criteria. The Infinity has more glass space and a "high-end" look, while the Softlite has better performance ratings across the board, and is typically a better value. They are both high-end choices that are directed at different buyers. The Softlite for ultimate performance and value, the Infinity more for beauty.
I'm not familiar with the Eclipse, and I don't consider Atrium to be on the same level as the other two.