Yes, I have exactly these same sub issues. It just isn't there the way the 1050 was. In DD, the performance is remarkable. But switch out to any other mode, especially the PLII and 2 channel modes and the sub goes away. I have to hit the trim and take it up all the way to get the sub back up. In 5 channel stereo it thumps like mad and I have to trim it down. Some of the modes just aren't driving the .1 channel as hard. My 1050 used to light up my Samson amps first 2 lights and occasionally the third (clip) light if I was driving the sub hard. This is actually the way the amps manual says it should be driven. But it is now only lighting up the first light and occasionally the second lamp if its trimmed up.

I wonder if there is anyone out there who owns both unit who could measure the output of the .1 channel and see if there really is a difference.
I think its mode specific. Again in DD the whole house rumbles.

Now I did my calibrations at a little lower levels mainly because we usually don't listen at THX levels. I didn't worry so much about the volume setting and just set my meter to 65 and brought the volume up to 0 on the meter with my center, then brought the rest to the center. THis left my calibration settings more like +2 0 +2 +4 +4 instead of being maxed to the plus side. So then when I couldn't trim up the sub enough for the other modes, I backed the calibration up 2 clicks
0 -2 0 +2 +2 to give me more sub without having it maxed all the time. Probably not the correct way to handle this at all but it got me a little more gain in the low end.