There were scalability issues with 8.0.1. Whilst we could build a new VM with the underlying OS and prerequisites, IBM was always required to assist on-site as only they knew the complicated and fairly undocumented procedure to implement a new IMS server to the pool. In 8.2.1, this has been amplified tenfold as the solution moved from Apache on Windows to IBM WebSphere on Windows, which is incredibly complicated and requires multiple levels of specialist knowledge. This makes it nearly impossible for our company to expand the number of nodes in the WebSphere cluster without accidentally introducing new issues in the said cluster.