I certainly understand, ounces = pounds, and all.
But
An XDs 9mm is 23oz unloaded, A G19 is 23.6 oz unloaded, and a G21 is about 30oz, unloaded. Heck, a G26 loaded up is the same weight as a loaded XDs, and you even get extra rounds, and can use a full size mag too.
Assuming an XDS with the 8 rd mag + 1 you are talking about a 3.5oz difference in 9mm going to a G19 with 15+1. or if you were talking full size G21/G20 10mm, loaded up, roughly 39oz.
That is 13oz difference to go with a vastly superior backwoods gun in 10mm vs the other mentioned calibers.( and 1-1.75lbs lighter than WJCO's SW500, unloaded!).
If not that, I would still say that a G19 is a much better option than the XDs at the same weight (except ammo weight, but same number of rounds without the spare mag) with much of the same advantages in capacity and ease of use for mentioned purposes, and at least then you can get some +P+ rounds for those backpacking adventures, and still have a reasonable chance of a followup shot...
Im not poo-pooing the XDs, its a fine pistol for what it is - but it does not shine (or even really place decently) on any of your 3 stated needs for the weapon. Guns like the XDs, Shield, G43, PM9/CM9, P938, LC9 - they are all basically one trick pony's for concealed carry, and relatively poor general use guns outside of that role.
With all that said, if you are getting it because you want an XDs, then drive on - I would still rock 9mm.