I've been using integration tools for the past 15 years and Jitterbit is probably the easiest I've learnt. The simplistic approach to build, test and deploy an integration is a massive positive. There code library is vast, so you should always find what you need, and if you get into any trouble their Support team are at hand. Which I must say is one of the best I've worked with!
The team release new versions of Studio and the Agent often, so the product is always improving. But recently had the opportunity to see the new release of the Studio (web based), and must say I'm excited to begin working with it and migrate our Projects.
This is a glowing recommendation, and NO, I don't work for Jitterbit!
We have Integration requirements (Jitterbit smashes through these), API requirements (again Jitterbit smashes through them) and connectivity to many different End-Points (can you guess what I’ll say?).