Drop outs... IO in or IO out? - Capture Buffer vs. Playback Buffer

So, lots of times I've struggled with a drop out and why this time I have a drop out. I've also struggled to advise others in the forum.
 
I'm getting ready to go do a field recording and because of issues last time with my Windows laptop, I'm going to use Linux to record this time. I don't have to do a live monitoring setup, so I don't need RME TotalMix to do routing within the RME UCX.
 
Anyhoo, I've used Ubuntu Studio for a while now for personal practicing, but I really haven't used it in the field to speak of. I usually need TotalMix. So, before going out I decided to run some tests.
 
I set up 8 tracks and recorded at 192 and then kept bringing down the sample buffer to try to cause a drop out.
 
This is where it gets interesting...
 
Ardour has two buffer meters on the control bar (much like Sonar has for the processors). While Ardour only has one DSP (digital signal processor) meter, it has two buffer meters. One is for P: or Playback and one is for C: or Capture. This is particularly interesting because you can see if the problem with the buffer is related to reading data off the disk (too many zillions of items in the take lanes) or writing to the disk -- full disk is too slow to write the wave files. It also tells you how many more hours of recording you can do to the destination disk if the number is less than 24 hours. It shows the file size (float 32 or 24 bit int or whatever), the audio sample rate (including round trip time) and these cool buffer meters.
 
Anyway, maybe lots of DAWs have this, I don't know, but I thought it was super cool when I figured out what it means. If we had this in Sonar, we'd have a much better indicator as to why a user was getting dropouts than we currently have.