I already posted some shots with R3 on my gallery.
Anyway, due to the reduction down to a width of 900 pixels and 8 bit grayscale any comparison between films is useless. You can give a picture every look you like, more or less grain, more or less sharpening, independent of the image source, no matter if from film or digital, converted from color etc.. .
In the end only the print counts.
To come back to your question: I compared it to Gigabitfilm, PanF, Delta 100, 400 and 3200.
Gigabitfilm was definitively better, but it's not available as 120 film, the alternative there is the Maco Ort25 with Docufine developer (if you have the material and technique to really use it's resolution). The R3 is better than PanF in Perceptol, it's better than Delta 400 in Perceptol or IlfosolS and its better than 3200 in Microphen. It compares well to the Delta 100 in DD-X, can't make a definite statement.
Anyway, for 120 B&W I switched definitively to it, it's too convenient to decide just before the shooting which ISO you gonna use. And with 6x9 I get 8 images per roll, which lets me adapt quickly to changing situations without wasting too much material.