Hi James, sounds like you got yourself a bargain!
Try taking some identical test shots with and without your filters though if you suspect they're cheap and nasty - they might slightly reduce the quality or contrast.
As for noise levels, we measured them as higher than cameras like Canon's 350D, especially at higher sensitivities, although to be fair, the Canon has a lower resolution and a sensor that's well-known for low noise. See:
http://www.cameralabs.com/reviews/SonyA ... e4ca.shtml
But yes, you're right: the benefit of Anti-shake systems are that they let you shoot at slower shutter speeds than normal, which could allow you to use slower sensitivities than normal, thereby reducing the problem of noise.
Do remember though these slower shutter speeds won't of course freeze action, so if your subject's moving, it could suffer from motion blur, even if anti-shake is ensuring the background's pin sharp. So if you're photographing people for instance, do keep an eye on the shutter speed.
I don't think people will object to the mechanical noise at the wedding, unless it's at a silent point and you're the only one taking pictures. I'm glad you mentioned it though as some people have questioned my comments about shutter noise in my review.
The best tips I can give you for the wedding, is to 1st, become familiar with your camera, especially what settings work well with people, and 2nd, try and visit the venue(s) before-hand to work out some good angles.
And even though you traditionally want to avoid noise, do consider taking some people shots without the flash under natural light, with higher ISOs if necessary. They'll make a change from all the harsh flash shots people will be taking, and people may relax more as they won't believe your pictures will work out! Do some tests before hand though with white balance settings, as you'll probably need to manually set this if you're shooting indoors without a flash.
There's soem great books around with tips - I'd advise going into a bookstore and flicking through a few to find one which suits your style. We're also planning more workshops in the near future, so keep an eye on Cameralabs!
Thanks for your message and hope you enjoy using your A100!