Contacted a guy who bought the Sandy Headers from Ebay, this is his reply..
"I was not happy with how lumpy my GS was running, having had a 1150 in the past I knew it should be better. Started with a K&N which made it sound better but didn't smooth it out any. Then added a Akrapovich end can which gave a slight improvement but still not anything like it should be, at this point had only one option left and that's the headers and I must say they have transformed the bike, throttle response is instant and it's as smooth as silk. The headers came the following day and at about half the price of the Remus pipes I can say I'm delighted with them. Hope this helps, regards, Chris"
Can't wait to get mine now!!