Any software has its own limitations. I have not come across any software that is 100% accurate since you can not model the problem 100%. There are many factors beyond our control and which can influence the results. What is important is not the exact values but the trends and if we are able to minimize a problem by a particular approach, the same holds good in actual. Also one has to know who has tested and characterized the raw material as it greatly influences the behavior.
There are some advances in Sigma Soft, Moldex 3D and some new softwares that are coming. The question remains, will there be database for many materials or a new algorithm is developed which does not need critical and accurate material data. One interesting point I would like to share is that I have been using Moldflow for last 20 years and about 10 years back users used to say the results are accurate, now after so many developments also users say results are accurate and I wonder, if results are so accurate then what for are the developments? Is it we are paying only for GUI? One thing I would say is that you try to use different software to keep the established players on their toes and make them focus on developments.
The simulations results have a qualitative accuracy for this reason many companies and the academia are working in this area. The reason is that all models use strong assumptions that can be weak depending on the material, geometry and process conditions. I can give an example for fiber filled injection molded composites. For short fiber composites in a center-gated disk test sample, we have found that the actual models fail to predict the orientation near the gates and up to r/H =39. The actual model implemented in most software is reasonably good above 39, but still prediction of fiber orientation near the walls is challenging. Additionally, the quality of the predictions reduces noticeably as you increase the fiber content and the thickness of the parts. These two conditions reduce the validity of the assumption used in the simulation packages. The area of interest of many software developers is the prediction of fiber orientation of long fibers. This is an area of opportunity because we are still unable to predict a reliable fiber orientation due to the semi-flexibility of the fibers.