What sort of issues are you having when you say youre not happy with the quality of the steam being produced?
Is it too wet/dry? too slow/fast?
Admiteddly Im using a 6910 - some slight changes that Im aware of to the steam wand but (I dont think) anything too drastic - its taken a little getting used to but Im getting a pretty good texture to my milk after some machine adjustments and (more so) technique adjustments
AM has posted a good steam test over at http://coffeesnobs.com.au/YaBB.pl?num=1227858558 - might be worth a shot to see how your machine compares?