With my Tacima I noticed quite an improvement in TV picture (on a 5-star Panasonic TV) when fed with the strong signal from the V+ box. Blacks are slightly blacker, but edge definition is a lot better. The benefit is less so with off-air signal supply, but I suspect our aerial isn't aligned as well as it should be (TV's in the back bedrooms use an aerial in the loft aligned slightly different and picture quality is much better), so I think I'll struggle to see the benefit anyway until the aerial is sorted.
However, I noticed little or no audible difference when adding it to the Home Cinema setup(CD/PS3/V+), whether the receiver was plugged into it or not. However, this is comparing it with the Belkin PureAV surge protector which fed it before (and now feeds it again), so maybe the PureAV is already offering some benefit.
Plugging the receiver directly into the wall causes a very slight drop in quality. In stereo the soundstage was muddled, where previously it was a lot more precise.
I too now bow out of this thread before the cable-atheists* arrive and tell us we're all wrong. If you can afford to buy the Tacima, try it. If it works it works. If you see/hear no benefit then at worse you've bought an expensive surge-protector.
(*I'm not a devout believer, I just consider myself open-minded and like to try most things once to see if they work).