Haha I still love my barenia kelly....but she is heavyam taking a break from lugging her around. The canvas strap I use from Chapman is perfect but it is also heavy...with rugged hardware. I think as I get older I just get tired of the weight....I have never owned a GP. For some reason they don't appeal to me though I know so many love them. I don't know about a 28 Plume, but my 32 Plumes do fit on my shoulder though its snug with the bag right under my arm pit It's not a long term comfort carry by any means, but if I need to I can do it. I don't know - I love the 32 Plume - you may want to revisit
It holds about the same if not more than a 30 B, and certainly as much as my 35 K. It's pretty roomy while remaining light and comfortable!
The “arm pit bag” thing is my issue with the GP. That said, the Plume 32 is very appealing! Maybe if the right color/leather combo comes along, I will jump. Interesting that you find the VN plume lighter than the Barenia K — that’s a pretty apples-to-apples leather comparison, which tells me the Plume is truly a lighter bag.