I have the standard G9 80 and yes my ripples a fair bit.
However I didn't return mine for a few reasons.
1 Only really seems to happen when hold with my left hand (so pressure on left of device). Therefore can be avoided by holding in right hand (which i do mostly anyway) or by using the kickstand.
2 It shows more on a plain dark background. Once I customised my home screens by adding koi wallpaper etc I see it far less.
3 Bought it when first out so using a quidco type deal got it for £170. Can't see me getting a better one for that price.
4 They already have an ICS pre build demoed on it. Seems that as they put a close to stock ROM on it they are going to bang updates out very quickly.
My new Archos G9 80 Turbo arrived today and I am going to have to return it.
I was prepared for some screen rippling if I pressed hard on the back but it is rippling with the most gentle of pressure, just picking the tablet up and holding it without adding any pressure is enough to cause the distortions. Even holding it by the very edge and letting it rest on my fingers causes it.
I assume this is worse than other's have experienced? I like the tablet and if I could get it swapped for one without this issue I would do so, but if a lot of them are this bad I feel inclined to just get my money back and get something else.