With this upcoming release of the PivotGrid controls in all platforms the serialized pivot grid collapsed state consumes much less memory. The amount of memory consumption improvements will depend on the particular layout (number of collapsed and expanded field values) being displayed when serialized.
The largest effects will be felt in the ASPxPivotGrid as the serialized stream size impacts the volume of data sent across the wire from the server via callbacks by ASPxPivotGrid. With the other platforms the improvements will be felt when the pivot grid layout is saved resulting in smaller external storage (an XML file, a stream, the system register, etc.).
With the previous blog about the Memory Consumption Improvements for Unbound Field Values you can see we have really spent some time on the core functionality of the PivotGrid to get the bets performance we can at this time.
Please let us know what you think.