I would go with the Hafler. Superior in every sense other than marketing budget.
Hafler Series Trans Nova 9505 vs Yamaha M80 Power Amps
Looking at both in my area. Both advertised at $1k and in great shape functionally and cosmetically. The hope is to find a quality power amp that can drive about any speakers, including my Thiel CS1.6's and Monitor Audio Gold GS20's, bringing out the very best in them. Any input/personal experience with either is much appreciated!