I have a sack I've only recently started using. My first beer with it is currently kegged and waiting for a tap to open up. Flavor is good/typical pilsner flavor. Color does not appear to be darker than, say, Avangard Pils. Unfortunately, I haven't sampled enough of the first beer to give much more than that.
Here's the lot analysis from my bag:
http://www.weyermann.de/pdf_analyses/Q180-001360-01.pdfI've done both stepped and single infusion with it. The stepped (148/158/168) resulted in much higher efficiency than usual but it may have been the rice adjunct that I used as well. I also saw a slight increase in efficiency on a separate batch that used 15% Barke Pils. I suspect that the potential is higher for this lot than typical but I'm waiting for another mostly-barke beer before making this decision for this bag. This 'higher potential' occurred once before with my first bag of Avangard Pilsner, but subsequent bags did not stay that way.
Hope this helps.