First, I did talk (actually email) and was told,
"Sean you are on the cusp, could go either way. It might depend on how you
wear the pack. I'd say order whatever your instinct tells you, load it up
with a good "typical" weight and wear it around the house. You can always
exchange it then if you decide it's not correct. Other option is to order
both and return one.
I don't have the money to order two packs. I asked the question here so that I could increase the chance of getting the correct size pack on the first try.
Next time I will make sure to let everyone know of all communication exchanges between the manufacturer and myself before asking a question :-)
Thank you Gail for the helpful info.