alclad is pretty much the same as far as backing goes as far as i know, it's the same kinda stuff and the earlier spaz stix looked pretty similar, spaz stix actually do their own black backer though, and obviously the chrome kicks alclads ass and throws it out in the street
and yeah the spazzy blue with chrome behind looks fantastic in pics, and i'm told they don't do it justice !
the only downside is it's not so versatile as standard colour paints, being translucent you can't really fade it etc (I tried after being warned not to, it failed
)
edit: do you find backing it with white gives it a 'brighter' finish since the white reflects any light that gets through the chrome, and have you ever used the faskolor white as chrome backer at all?