Has anyone done a direct comparison of a these two units.
Has the bloated bass been tamed? What are your thoughts.
There is a big improvement, especially in the area of the mid bass bloat. It is also a bit quieter, but still is a bit noisier than the BAT VK-50SE. Same huge soundstage with tonal improvements. The 6h30 tube is a real nice improvement. If you have to stay with ARC, I would highly recommend the Ref 2 MK II.

Other fine preamps to consider are the Aesthetix Callisto, BAT VK-50SE and if you want solid state, I have a friend singing the praises of the CTC Blowtorch.

Good luck.
Has anyone recently compared the two ARC preamps?
I compared the two ARC preamps 11-20-02 and the ref pre bettered the LS-25 MKII in sound stage and dynamics slightly, but the over all presentation was smoother and a little more tube like where the 25 is very natural but non forgiving. I preferred the ref pre but the diffence in cost is what you have to consider, out of my range.