Here's a great & helpful thread about Zeintops on boxa.net, to which I recently added my experiences of installing a Zeintop DIY kit. The experience was about 90% positive.
http://www.boxa.net/forum/index.php?showtopic=35757&hl=zeintop&st=120
I do love the way the car looks with the top, although I'm still adjusting the fit to some extent.