TM1 is one of the best business application development platforms

Pros and Cons

Performance is amazing because of it's in-memory OLAP engine.
With a little experience, it's a great rapid deployment platform that can model just about any business process.
It is actually quite scalable considering the amount of RAM that can be installed on servers nowadays.
Easy to setup and migrate to a new environment.

It lacks a pretty user interface.
Learning curve can be high for non-technical person.
Getting data out of the system could be easier.

Return on Investment

With the right mix of consultants, contractors, and internal W2 employees, ROI can be as high as 160 hours saved per month for a $100K project.

Likelihood to Renew

This is a planning developer's dream. You feel like you're given a blank canvas with all the right tools to make it an artwork. It is the future of business application development.

Likelihood to Recommend

Software may not be cheap but a cheaper version (IBM Cognos Express) is out there if you don't have that many users.