Thanks for the great info (
http://beta.focusrite.com/releases/focusrite_usb2_drivers/ Look for the Focusrite USB2 Drivers 3.2.2 and Scarlett MixControl 1.9b12)
Since weeks I tried to figure out, why I'd go up to a RTL of ~ 29ms (256 samples, balanced mode) in order to prevent my system to have drop outs.
With the new driver version I'm down to a RTL of ~ 15ms (64 samples, balanced mode).
Nevertheless: next investment will be a RME PCIe solution. It is no fun to play with TH3 with that latencies...