In my opinion, this software does not have any cons in terms of performance or price if you are planning to use it for medium size data storage purposes (upwards from 10 TB).
If your needs exceed those parameters then I recommend buying more expensive solutions such as S2D/S3C series devices by HGST etc., but please refer also other products reviews here at DigitalOcean before making decision because there may be something better than what we already know about VNXe device line! Pricing - good value product; easy migration path when new versions come out which means less need / work done migrating existing environment over time into newer version without downtime periods where old node gets retired during upgrade process ; ability do full cold cache tiering across all nodes using LUN mask mechanism so can utilize whole physical disk space available within single pool regardless.