It depends on what you're trying to do. For myself, I wanted to OCR scanned documents and I've been moderately successful using ScanTailor to process the image

It depends on what you're trying to do. For myself, I wanted to OCR scanned documents and I've been moderately successful using ScanTailor to process the images and then Tesseract to OCR the result. Certainly, it's far from perfect and the documentation on Tesseract and its options is spotty, but I've been moderately happy. As a note, I've had better luck with the current trunk in the git repo of Tesseract than the point releases. Some of the older versions of Tesseract modified the images when processing to a PDF and this was unacceptable to me.