I tend to think the issue is unlikely due to GUI processing side of things because the meters in other plugs and in Sonar itself behave fine.
 
I might try ASIO....but I honestly dread installing drivers, especially replacing drivers.  No telling what might go wrong, or be introduced, into an otherwise stable system.   What are you guys implying about the alignment issues with non-ASIO drivers, are you saying all the audio tracks will be out of alignment by roughly the same amount across an entire track?  Or will alignment issues be random?   I wouldn't be so much concerned about something slightly & inaudibly out of alignment that could later be corrected by merely sliding over all audio tracks one time if need be.  But if the alignment is going to be imparted randomly and inconsistently throughout a track then that might be a real problem to be concerned about.  This topic is all news to me......I always thought Sonar compensated for latency issues.
 
As it turns out, there seems to already be an ASIO option in Sonar....does that likely mean I already have RME drivers installed that support ASIO as part of the RME driver package?
 
BTW, I just remembered WHY I stayed with WDM drivers.....I had an M-Audio card in the system initially, so I kept it in the system so older projects would open up and run without issue.  But in this new DAW I am ditching the M-Audio.  The only card used inside Sonar will now be the RME FF400.  So maybe I can use ASIO after all.
 
Sonic