Of course this might not be everyone's cup of tea, but the decor is much more different - the Novotel is very modern with the whole headboard lighting up, lots of glass in the bathrooms (magic glass too), wardrobes etc are the "integrated" roof to ceiling type with dark woodgrain, all have a modern look. Almost like an Aloft (but a step nicer IMO).
HIX is still nice and clean, but much more "traditional". Of course, you can't beat free though, so might not be worth switching.