Maybe Mohawk means that the plantsupport is different render-wise.
Carrara for sure and Vue in particular cases handles objects, like plants/trees etc., better than TG2.
I think the reason for this is that the background of the software is more orientated on modeling, texturing, lighting and rendering models, so very object-orientated.
The power of TG and in the meantime also it's weakness is that the renderer is more designed for realistic rendering of terrain, water and atmosphere.
I expect great improvement of TG in the field of object-handling and renderquality, although very good results can already be achieved.
Martin's (Hedenstroem, aka HowieFarkes) scenes depend heavily on its models and I think the current TG-engine can't yet stand up to Carrara's when it comes to handling and rendering objects. With handling I mean things like assigning lights to specific models etc.
Maybe also in general people are a bit "scared" to dive into TG and getting to learn all the ins and outs of the many functions, noise flavours etc. etc.
Martin