Pros
I've worked in multiple lines of business (LOBs) at CIBC and they're wildly different - largely dependent on the culture created by the VP or SVP at the head of the group. If you're able to focus on your value and your contribution, without letting people "get in your head" then it's pretty easy to be successful and stand out wherever you choose to go.
Kontras
Like many places, CIBC has a "do more with less" culture that will attempt to squeeze as much value from your time as possible. That's not a bad thing as long as you're really good at setting your own personal boundaries. It's likely your manager won't help with that - in fact, it's likely your manager is struggling with the same thing. This isn't a problem that's peculiar to CIBC, of course. It's still good to know what you're getting into. Again, different groups with different leaders will have different cultures. No blanket statement will prepare you for a full experience at this bank or any other.