@AquaBreath, if you look on Dive Rite’s website, this is what it says for the TravelPac:
With its compact and streamlined design, the TravelPac’s 25 lbs. (11.3kg) of lift will support one 80ft3 (12L) aluminum tank with up to an additional 10 lbs. of weight.
And for the Transpac XT, I would choose one of the Travel Wings (EXP or XT), and this is what it says about the wing:
At 25lbs/11.3 kg of lift, the Travel can accommodate one 80ft3/12 L tank with no more than 16lbs. of additional weight.
I don’t know why both wings have 25lbs of lift but the Travel Wing can accommodate 16 lbs of additional weight whereas the TravelPac can accommodate only 10lbs. I guess the Travelpac is probably less buoyant. However, if that is the case, 10lbs seems a bit close for me since I currently require 12 lbs with a 5mm wetsuit. I’m very floaty at the moment so need a lot of weight to hold a safety stop at the end of a dive.
In addition, I don’t believe the TravelPac is modular, meaning that the wing is permanently attached to the harness, whereas you can take the wing off the Transpac XT and replace it with a different wing if you need more or less lift. The Transpac XT can also be used for double tanks or sidemount just by changing the wings and adding some accessories.
In addition, since the Travelpac is a “travel bc” the materials used are lighter, which usually means not as rugged or durable than a regular BC.
I haven’t decided which to buy yet, but I think I have eliminated the Travelpac due to its lift being not enough if I switch to a thicker wetsuit. And I think Transpac XT is more flexible in that way. My current choice is between the Transpac XT (soft back) vs. Transplate (hard back).
That stone thingy is simply called “a weight” here in North America. So we would say, “I put a 2-lbs weight in my left weight pocket and a 2-lbs weight in my right weight pocket for a total of 4-lbs.” Something like that.