What do you like best?
There are a number of features, such as the template builder and contact-level mailing reports which my team uses on a continual basis. When working with these simplest parts of WCA, the thing that stands apart is the plethora of hidden functionality. These range from free Litmus and SpamAssassin testing to Hotmail and sender score deliverability reporting.
Of course, there are also more advanced features. WCA supports the creation of exceedingly intricate programs (automated/triggered series), it ties into mobile and social efforts natively, and can serves admirably well for lead scoring, lead routing, engagement reporting, content management and delivery, and a number of other functions.
After working with this tool for several years I'm still exploring new functionality which is simply unavailable from most other ESPs/ campaign management tools/API handlers/+. WCA wears many hats and makes it simple for my team to expand our communications program while driving synergy across the company.
What do you dislike?
While the training, knowledge center, and various blogs/social groups have a wealth of knowledge, the onboarding process (when I started using WCA) was very much a "we'll throw you in the pool and you'll learn how to swim" experience.
I'd recommend weighting curiosity heavily in your hiring decision when looking for someone to use this system--it's a poor fit for those wanting a done for them solution. As a client across multiple orgs, this need for self sufficiency has extended to customer support, sales, and technical support.
Recommendations to others considering the product
Determine your objectives upfront and ensure they're aligned with what WCA offers.
Find an experienced partner to train you and show you the ropes.
Do your homework throughout the onboarding and ramp-up period. I strongly recommend the certification training offered for WCA; to date, I've found it to be the best source of information about the platform.
What business problems are you solving with the product? What benefits have you realized?
We've dramatically expanded our usage of WCA to reach our customers around the world. Few solutions would have allowed us to evolve as gracefully from blasting communications in 1 country to individual conversations with customers on 6 continents.
Along the way we've built APIs with our proprietary systems and a range of specialized tools to tie WCA into CRM data, product data, sales data, support data, etc. It handles the load with ease.