Just to add to the inertia - I have a DIR-655, 1.32NA, Shareport v1.1.0 R1 on a 2 desktop (wired), 3 laptop network (mixed XP/Vista 32, 2 wireless, 1 wired), with a DNS-323 and two Ximeta NDAS for storage, and DGS-1008D for the additional ports I need. I've connected a USB hub to the router USB port and connect an Epson CX4800, SanDisk CF card reader and USB harddrives to it, plus the occasional memory stick. The DIR-655 uses Jumbo Frames.
In general, it works very well but every couple of days it seems I'm having similar issues with Shareport not connecting reliably and the DIR-655 being very slow unless I reboot or power cycle the router. Often I can't get to the admin pages of either the router or the DNS-323 until I pull the plug.
While I do mind not having a stable configuration I can work around it, but it's even worse when my wife want to do something simple, such as printing or scanning. I want her to be able to rely on the system and not have to get frustrated and call me to fix the problem.