Pros
There's a lot of autonomy. If you have a solid reason for something new then it's fairly easy to get the support for it. Everyone is very open so if you have questions you can chat them or just walk over and talk to them. Something I really like is the flexible hours. Depending on your location the IBM campus can be a long commute but you can reasonable choose your work hours to beat traffic. Working from home on an as needed bases is also fairly common. The management at least the original StoredIQ management is really good. I'm not saying the IBM management isn't good just that I work mostly with StoredIQ management. StoredIQ has been dominating IBM sales so we get a lot of freedom to do what works and help transform traditional IBM processes. From IBM's perspective you're still just a number, but a prime number at least.
Cons
Since being acquired by IBM the development process has slowed a bit and technical debt get less consideration. I think that's comes more from IBM wanting to make money on features rather than investing in a rock solid product. A lot of the software is home grown which can make ramp up for a new developers a bit challenging. It's still generally python and javascript so if you have solid skills in either of those areas it's just a matter of learning conventions.