Improved my 1150, but not by £1000+ that a new set would cost.
I paid £400 for a used set ( a few years ago), that was just about the amount of improvement i gained.
Simply fitting re-cond/serviced shocks will also make the bike feel better, so bare that in mind when people state they made my bike feel like new.
The reason being the shocks they were riding around on were knackered and not that the ohlins were that good.
They're good, but not £1000+ better.