The main thing that has me unsure of what to choose is the 90% tops of the 830 vs the 75% tops of the 620. I'm leaning toward the 620 mostly because of the shorter loft height (50mm vs 55mm). I face and bowl lather equally and find shorter lofts can handle both better than higher lofts. But my experience and conjecture are both based on my history with badgers. I've heard the 830 can get floppy once broken in and isn't the greatest face latherer. But those 90% tops seem so appealing. Just how much of a difference does that extra 15% make regarding face feel?