In my experience low grade PRL don't look much different than regular CRS. Depending on the breeder and how many generations that line has been line breed you *might* see things like larger sizes and larger percentage of offsprings with similar patterns to parents (if both parent have the same pattern). But that really comes down to what traits the breeder has as targets and how many generation of line breeding has occur.
Generally, those are good questions to ask the breeder if you are unfamiliar with their line. Even more so if there is a lack of photos and/or grading system in place.
Things like color doesn't really come into the equation unless you get the very high grade ones - and I have seen very few domestic high grade PRL / PBL lines.
I purchased some APB PBL and I am fairly happy with them. A fairly large percentage of the F1s have similar patterns as their parents. Color is not as solid of some of my Nishiki JPRL, but wasn't really expecting that for the price. I think with some work they have very good potential, if not they are still better than most non-PBL CBS i have encountered for sale.