Registered Servers (with or without CMS) are an incredibly useful feature, however once the number of instances exceeds 20 it can become cumbersome to find instances you are looking for. This is especially true when organisations do not use logical groupings or naming. One of my current clients has 300 instances stored inside a CMS instance contained within many folders. It is very time consuming to run queries on a subset of instances without using the workaround attached to this Connect item. It would be much easier if the filter feature was added to the Registered Server Panel.
Many organisations that use Registered Servers keep duplicate copies of each instance so they can filter according to what they foresee will be needed in the future. I.e a folder structure for system/application and a duplicated folder structure for SQL version. This is redundancy and requires additional overhead for management. If users had the ability to filter, the Description field could be used to hold metadata tags
such as system/application, they would no longer require duplicate folder structures (because they could filter on the tags).