Yeah, thinking about this, really, I don't think anyone actually reads positive feedback other than the receiver. When I'm checking out a seller, I look at the percentage of positive feedback, and if there's negative, the percentage of that, how recent it is, and sometimes I'll read some actual negatives and neutrals.
But there's not much reason to read the positives. The main benefit of the positives are to up the seller's ratings. As a seller, I receive some glowing feedback and some as simple as "thanks". One buyer just left a period, ".". But it was positive, added one to my positive rating and that's all I cared about.
I'd just post whatever and quit worrying about it. Bopper's wording is nice, it communicates to the seller how you feel, and it adds one to their rating.