This excellent summary was written by Dan Hess of the Ironside Group.  It provides insight into the use of levels from a TM1 dimension for use in Report Studio (and indeed Cognos Express Xcelerator and Cognos Express Reporter).

TM1 and Report Studio – The Mystery of the Missing Levels

As many of you know, TM1 has become a major component of the IBM Cognos BI application offerings. As a corporate OLAP solution, there are a number of advantages to utilizing TM1 versus PowerPlay; from faster response times in larger cubes to the capability to handle vast volumes of data. The expectation of course is that the application will work within the IBM Cognos BI infrastructure, specifically within the user facing studios that make Cognos a best of breed solution. While this is true in most aspects, there are a couple of “work arounds” that must be implemented in order to optimize the user experience with TM1 as an MDX based data source.

The IBM Redguide for Cognos 10 highlights the features of IBM Cognos BI version 10.

IBM publish their own books for use with their products.  The IBM Cognos 10 Redbook is available here.

Cognos iPad app now included with Enhanced Consumer license and mobile server now included with Cognos 10.1.1.

IBM releases Cognos 10.1.1 including native iPad app and improved Business Insight Advanced report authoring tool and connectivity to SAP and TM1.

TM1 9.5.2 includes major changes that will support very large numbers of parralel users and massive improvements to performance when used as a source for Cognos 10.

Despite the small increment in the version number, (from 9.5.1 -> 9.5.2), our understanding is this is a major release with significant changes to the database locking mechanism, multi-user access and parallel processing.