I'll tell you, viewing it in person for the first time is appears/feels substantially bigger than the Six, but setting them side by side, and back to back, I'm surprised at how big it isn't.
My orignal desire for a Redhawk .45 Colt was a combination deer hunting/target shooting/home defense gun that could be loaded up and down the scale. I thought 5.5" inches would be the perfect combination of hunting power and packability (the 4" didn't exist and I wanted it DA). Though a 5.5" would be too long for CCW, this 4" won't be too much different in a nice pancake holster (albeit thicker) than my XD40.
It's also got me thinking about trading my SRH for a Puma 92 in .454 (I got the SRH when I couldn't find a Redhawk).
I'll be headed to the range next Saturday, so check back for a report.