Just having my timberframe house done with it today. Hard to get information on it, but what I could find merited, in my opinion the extra cost. Heard that WHICH magazine voted it No. 1 of all insulation material, but I can't substantiate this. Apparently alot of timberframe builds on the continent are using it. I liked it from the point of view that it fills in all the holes etc. better than would be achieved with fibreglass and also it sould'nt sag over time.