Thanks all.
I took xtra care to get everything sharp. I laser collimated the secondary to get the laser spot dead on the centrespot on the primary. Before attaching the camera I put on an eyepiece and star collimated the primary spot on. Guide stars with the off axis guider seem a little brighter and sharper now too
Guiding the Omega was a real struggle as I was nearly nodding off while doing it, as it was around 2:30 am and my 2nd big night in a row.
Scott