I assume the reference to the Nova is some sort of dig at the Astra?
I am not saying that Vauxhall are great - I think they are about average - but having driven both a 2.0T and a 118D the Astra wins hands down on fun, looks, performance and ability to modify if you like. BMW is overpriced, more reliable but massively expensive to repair when they do go wrong.
If you want to soften the blow of selling the Zed and getting a more sensible car then the 118D is a big step down in my view, the Astra would sit somewhere in between - depends what you want really. And like I said, the 1 series BMW is fugly