Fantastically easy to use - it simply does the job at a very reasonable price.
Very easy to import almost all types of geospatial data formats and elevation daa.
Very quick to render images and models. Able to create "fly throughs" for presentations, videos, etc.
Conversion of file types and changing of projections is as easy as it could be. Only a limited amount of knowledge about geospatial data and projections is required.
A very reasonable price for a licence ($500 I believe). Review collected by and hosted on G2.com.