Hi,
I have a DIR-655 A@ version and I have been VERY happy overall with it. Let me say that as your research has probably pointed out, Other folks have not had my experience.
If you can go to the store and see if you can find an A2 version of the hardware you may also have as good luck as I have had....It "seems" that the A4 versions are slightly less stable, but that may well be me using "Rose Colored Glasses" when reading these forums....
Then again, maybe its just statistical dumb luck....
SD1