Geoff, the best mod I have made to my GSO 12" is also a cheap and simple one. Unbolt the two halves of the base, go to Mitre 10 and buy a 305mm lazy suzan bearing for $27.50 and a longer nylon locking bolt for $.75, follow fitting instructions making sure that centre of bearing is centre of base, bolt two halves back together using new bold and 6 old cd's as shims between base halves, these can be adjusted by adding removing to get it just right, then tighten bolt until all free play is removed between two halves, AZ motion will now be as smooth as silk and can be adjusted so it can be moved with as little as your breath or as much as a shove. Do it, you will not regret it, tookl me about two hours to complete. BTW, the bearing will support 80Kg's so you have no worry about weight.