Admittedly, I'm not a trained expert in administering or prepping either one of these tests. But I took the liberty of doing some research for you about these two tests, and I hope this helps! According to my research, these tests have more similarities than differences. More importantly, the kind of English you've learned and what kind of learner YOU are is how you figure out which test you should take. The IELTS, for example, is designed by the British Council, and so it is given in British/UK English. The TOEFL is given in United States English. It's all English, but there are some differences in spelling and grammar, as well as pronunciation and the sounds of the dialects. Also, if you don't like speaking to a real person, or if public speaking is scary, avoid the IELTS. Both of these tests have speaking sections, but for the TOEFL, you speak your answers to questions into a microphone. IELTS has you give answers to a live test administrator. Lastly, the TOEFL is made up of many multiple choice questions, which makes it better for people who take those sorts of tests very well. IELTS is more memory recall. So, choosing the test means you really need to know what tests work best for you.

Easier? I thought the other way round, especially due to the academic writing task of describing pie, bar charts etc.

IELTS is a little easier,as the vocabulary of TOEFL is largers that of IELTS,and on the other hand,the oral English part is a little different,you can speak with people of IELTS,but you have to speak to machine of TOEFL.