I can only answer some of these questions. The 1010s will have slightly lower latency. Mine runs at 16/2,
I sometimes wonder about numbers like these and if I'm doing something wrong or if it's incredibly hardware dependent. I've never ever come close to running at 16/2 in a stable manner. 128/2 I could run reasonbly stable with the Delta 44. Now with firewire it's harder still.
Do you really get this without xruns? Any magic tricks? How much have you tweaked your settings to get there?