I am currently evaluating QRecall. This is what I found in the logs after trying to merge:
Action 2012-10-30 11:15:48 -[PackageList sizeEstimate]: unrecognized selector sent to instance 0x11b345150 Action 2012-10-30 11:15:48 An internal program error occurred. Please report this problem to the developer.
Robby discovered a bug in the merge logic. The merge was failing to deal with items who's content had not changed, but who's metadata had and that metadata included a large amount (more than 20K) worth of extended attributes.
If anyone else is encountering this issue, you're welcome to download and install pre-release version 1.2.2(1):
Download the QRecall 1.2.2(1) disk image. Open the disk image and launch the Install QRecall application.