The only MIDI interface I've used without a problem is the Frontier Design Sierra, which connects to their Dakota PCI card. It has been rock solid through MANY generations of CWPA and Sonar, Presonus Studio One, and demos of a variety of other DAWs.
I think part of it is the fact that it is a PCI card (a serial port connection should be just as stable).
I think a bigger part is that way back when the devices were designed MIDI was still a staple, and the engineers at Frontier Design put a lot of effort into 'details' like stable MIDI timing.
I do know that eventually I will have to leave this set up behind, but for now I will probably switch from Intel back to AMD because most of the AMD motherboards still boast 'real' PCI slots, while most of the newer Intel (1155, 2011) motherboards are briding PCI to PCIe, and in some cases they are not providing 5V to the PCI slots.
I've tried a handful of recent motherboards, and the bridged slots don't seem to be causing a problem, BUT, I get maybe a day or two for these tests, so caution/conservative approach suggests that the AMD might be the trick.