I have a nylon, 10'x11' Springbar knockoff made by Coleman back in 1990. It's not a bad tent, but not very stable and storm proof. I thought the Stormfly might help with this, so I contacted the fine folks at Springbar and they were confident the two would be compatible. I placed my order and received it in about a week.
The fly fits my tent as it should. I love how the full length pocket zips over the ridge pole locking the tent and fly together. I went camping with a group of friends for three nights in up state New York last week. With eight guy straps, the tent was very stable during some gusty winds. There was no rain, but it was VERY dewy two of the mornings and the tent was dry. The nights were pretty chilly, but the fly seemed to help hold in the warmth.
Overall, I'm very satisfied with the fit and quality of my Stormfly, and setup is very straight forward. When I upgrade to a Springbar tent, which I will, I'll already have the fly.