Hi Eric,
Are you an Azure, AWS or both shop? I can only speak to Azure, since that's all we have at the moment. The big question I would ask is how much do you use the daily details? The multi-cloud connector does some preprocessing before loading the data into Apptio and the reports, so some of the granularity is harder to come by (it's in a hidden table). I'm still working my way through the data and how to use it. And to be honest, how my business users need to use it. Our company is fairly new to the Cloud party, so there is a lot of flux anyway. There are benefits to the MultiCloud connector, but just be careful. I think eventually everyone will have to move over anyway - it's just a matter of when you want to bite the bullet.
Part of my frustration is that I misunderstood what was going to happen when I moved to MultiCloud connector and v106. I was expecting quite a different result than what I got, so my expectations and reality were misaligned. I'm still working to get them back together so my company can move forward successfully with the reports that are out of the box. I'm sure I'll get there, it's just going to take time and patience.
Good luck with your journey!