Well, Vray is a separate renderer for Max...
I've worked with all the major 3d apps and for modelling architecture that isn't curved SketchUp is a superb tool. Very fast and if you use it right it creates good clean geometry.
As all apps it has it's weaknesses. True mathematical curves is one of them but for most things it's a very good modeler.
As for renderers, Vray for SU is not in par with the Max version. There will be a version 3 someday but when is not known by me.
I use Thea render now and am very pleased with the quality and fantastic integration.
The developers are very good at listening to the users and are making fixes very quickly. Unlike Vray. If you haven't tried Thea please do. It's the only renderer I know of that can use both CPU and GPU together for rendering.
In the past SketchUp could have a hard time with heavy geometry but much of that went away in the latest versions. I've imported Revit models and even three different large Revit buildings into the same SketchUp file and worked with them without problems. Navigating the Revit file with just one of the models was much slower in Revit than in SU.
There are a lot of exiting SketchUp plugins newly released or coming soon. Thomthoms SubD brings sub division modelling to SketchUp.
Skatter for scattering render only vegetation and much more and LSS Arch for dynamic parametric modelling of walls and windows and such. Viz is another exiting parametric plugin in the making that will bring Grasshopper like modelling to SketchUp.
WrapR is a upcoming UV mapping plugin that will have a SketchUp friendly interface and Animator by master Fredo is a parametric animation tool for SketchUp that looks absolutely great.
And if you still want to render with Vray for Max you can always do like Ronen Bekerman or Peter Guthrie and model in SU and export to Max for rendering.