Pros
Marketing Cloud offers a ton of great solutions. They are (mostly) fully integrated, which many competitors can't say, and the individual solutions are leaders in their respective areas. The former ExactTarget culture still exists to an extent but is fading over time. Marketing is a growing area in most companies, so there is plenty of room for growth. Being a part of Salesforce is a benefit from a company values perspective. The 1-1-1 model makes me proud to work for an organization that gives back.
Cons
New AE product enablement is embarrassingly bad. The first 12 months are sink or swim, and aside from self-enabling yourself, the territories are hit or miss. Sales reps that have crushed their quota at other companies often struggle due to poor territory carves and slow enablement ramp time. Furthermore, Marketing Cloud basically acts as its own company within Salesforce. Collaboration with the CRM business is weak at best, and Marketing Cloud's biggest competitor has been its own internal solution, Pardot. Last, sales managers here are mostly just that, managers. True leaders in management are few and far between. For example, struggling AEs are mostly on their own to figure it out, which is resulting in higher AE turnover.