A new Ford/Titan diff sold on eBay recently for £1150ish. That was new from Caterham but the last one I think. I hope the buyer gets lucky and it's not a screamer! I found as well as spinning momentum away it also spins expensive CR500s away, I lost 2mm on the unloaded wheel with no notable wear on the other 3! No difference in noise in normal driving that I've noticed, just grumbles a bit off the drive, t-junctions and very tight turns, as expected really. It was a great upgrade for me, car didn't make sense with an open diff.