Yes, I know several companies using DECIMM, and being quite happy with this software.
You can do full blown TCAD simulations and mixed mode simulations (i.e. simulating a small circuit where some elements are described by SPICE models, and some - by TCAD simulations) without being an expert in TCAD (things like physical structure definition, meshing, etc. are much easier to do as compared to traditional TCAD tools and flows).
Whether you need this or not is a separate question - and to find that out, it would be best for you to contact Angstrom DA support, which, as I heard, is very good.