Difference between 觉得 and 认为
Yes, 觉得 expresses more of what someone thinks based on feeling. 认为 expresses more of a person's opinion based on considerations and beliefs. As such, 认为 is always stronger than 觉得 when communicating thoughts. There are cases where the two words are not interchangeable:


When expressing a strong belief:


  在过去，人们认为喜欢抛头露面的妇女是不守妇道的。 In the past, people considered women who
  appear in public to be lacking in virtue.

When expressing a feeling:


  我觉得很遗憾，这件事不该发生的。
  I feel very sorry. This incident should not have happened.



Where they are meant to communicate thoughts, although interchangeable, there is always a preference of one over the other: 


When expressing a casual thought without a line of reasoning:


  我觉得这篇文章太深奥了，就算让我再读几遍我也读不懂。 I feel that this article is too
  profound. I wouldn't be able to comprehend even if I read it a dozen
  times.

When expressing an opinion with a clear line of reasoning:


  我认为这篇文章太深奥了，使用的词汇不是一般人都能看懂的。 I opine that this article is too
  profound. The vocabulary used is not what an ordinary person can understand.