well I am not an expert but blender can make models just as realistic as any other modelling app, you just have to know how;).
things lik maya/ are slightly more mature blender and so there some tools are a bit more polished but over the last year or so it has caught up. to be honest models can be made to do the same things regardless of the software used to create them, they just have different workflows, the only real limit is the skill of the person using. most people will usually prefer the one they learnt on.