Very useful feature on scenarios where you have a recorded midi data that doesn't fit into the tempo of the project. And you wanna change the tempo without altering the timing of midi data. There are different situations that lead to this and there are many threads on old forum where people request this feature for various reasons. This is still do able in CbB with complex procedures like stretching the midi clips post tempo change or using other methods like 'Set Measure/Beat At Now' or 'Fit to time'. The problem is not only that these procedures are bit complex they don't easy provide accurate result.
Recently figured out this is way too easy to do in Cubase and S1. In S1 just change the Time base in inspector from Beats to Seconds and change the tempo. Easy-peasy! Its just the same in cubase you have to change the Timebase from Musical to Linear.
What's more surprising is that CbB actually has the same feature for ages! In inspector change the Timebase from Musical to Absolute. Only it doesn't work! The manual states that it will work but it doesn't work. Either this feature was given up half way under development or it ended up not working due to bug.