If it works, stick with that specific bridge chip.
Asus and Gigabyte were using two different bridge chips.
IIRC, The MOTU 424 PCI card preferred the bridge chip used in Asus motherboards.
 
Echo and Lynx were particularly finicky with bridged PCI slots.  
M-Audio and RME worked with just about anything.
 

stickman393
 
Based on the chipset description, it would seem that the adapter does implement a bridging solution. 
JonD, if you know more about this, can you share?

I was only referring to the bridged PCI slots.  I understood Jim to be speaking of the same thing, and not about the chipsets on the adapters.  Of course, I could be wrong...
 
Bottom line is that it works for you and now we have the adapter model - facts that might be helpful to someone down the road.

@Jim, @Jon - Thanks for the extra info. This is really interesting.
 
So far (my configuration) seems pretty stable.
 
(The only problem I get is the occasional "Audio engine has unexpectedly quit" when I press STOP after playback or recording. But I used to get that before on my old DAW, so I don't blame the PCI adapter for that.)