I had tried the OCR function in v2.5.205 and found it to be spotty. However, consistent with IainB's experience with v2.5.211, when I had upgraded to v2.5.208 several months ago most of the issues disappeared—when the fonts in the original were standard (e.g., Arial, Times New Roman). I hope the function has continued to improve in v2.5.211, since I have been downloading an increasing number of documents using human-readable, but less standard fonts that the OCR in v2.5.208 has had a great deal of difficulty converting to text.
Despite this issue, PDF X-Change Viewer is still far and away the most versatile FREE PDF reader I have found.