The organization of the tool isn't exactly intuitive at every turn. I feel they overcomplicated the design.
The customer service and account management has been our largest struggle. We're likely to switch tools for that reason alone. It was very difficult to get it integrated with salesforce and took 3 times longer than expected due to intermittent support from the Eloqua team. Additionally, we felt like we had nowhere to turn for assistance, even from the start. The communication from day one has been a struggle.
While we're finally running automated campaigns, we feel that there are better options out there that integrate more effectively with Salesforce. Additionally, as we are growing rapidly, we need a marketing automation solution that can support us as we create more complex campaigns.