Analytics, the reports are very basic and often limited. We find it easier to pull any demographic reports or deep analysis on our lead funnel pipeline from our CRM system.
No calendar for scheduled emails or overlap conflicts. A lot of filters and customization can often lead to gaps in marketing and overlaps in emails. Also, for any drip campaign it's hard to give exact dates on when campaigns will be emailed depending on the overall complexity.
Underutilized. Its hard to get approval for complex campaigns when you also have to explain the logic problems to management that cause gaps and overlap. I do think the new Engagement Engine was a solid step in the right direction.
Its still planned as a vital part of our marketing strategy but needs to be utilized better.
Really consider if you have the time and bandwidth to use this tool. Templates, plans and preparation needs to be made in advance for a smooth rollout. Marketing automation will never give you true automation unless it's planned well in advance.