Earlier versions of .NET (i.e. 2.0) had a very poor implementation of GZip/DeflateStream which was much slower and took longer than the equivalent compression routines provided by SharpZipLib excellent implementation.

To configure ServiceStack to use the deserialization libs in this project add this to your AppHost:

StreamExtensions.DeflateProvider = new ICSharpDeflateProvider();
StreamExtensions.GZipProvider = new ICSharpGZipProvider();