It certainly won't be gray concrete. It will be shades of grey.
I haven't seen any posts Queationing the structure of it or its shape myself, more the appearence of the outsides.
I am more or less in the 'I don't really like it' camp for what I have seen so far, although as I have said before, I reserve judgement till at the very least the sample bay is up in a month or so.
Out of interest, what are your top 3 or 5 new build hotels in Manchester opened in the last 5 or so years? Purely for a baseline and comparison etc. The question is open to all.