R09: 0 to 30 trim.
R-09HR: 0 to 80 trim.
So 8 on the R09 and 20 on the R-09HR are indeed low, no matter what.
Not low according to some fancy numbers that Edirol put on there.
But low according to the parameter that the levels control: amplification and/or attenuation.
I.o.w.: what signal is needed for 0dBFS? Check the gain ranges the decks support.
I don't know about dBu's, but I've never set either set my R-09 or R-09HR at such levels.
It depends on the gear. And on the situation.
The combination of stuff (deck, mic, etc) makes more or less sense, depending on the situation.
In this case people see unusually high gain signals coming out of their pre. The deck can't take it well enough, and then it's
maybe the deck's fault.
Apart from how much you like your gear you also have to look at stuff in a practical way.
If the average deck takes only such and such levels and more expensive machinery maybe has your gain setting at the far end of the dial...
Maybe you need to look into adjusting something.