Mostly! (At the moment, it doesn't fully fix the slowdown associated with storing large binary files, but reduces it by 90-99%. We're working on improving to closer to 100% that by moving even the Merkle Tree storage outside the git repo contents.)
As for why git can't show you an accurate progress bar while fetching (specifically when using an extension like git-lfs or git-xet), this has to do with the way git extensions work -- each file gets "cleaned" by the extension through a Unix pipe, and the protocol for that is too simple to reflect progress information back to the user. In git-xet, we do write a percent-complete to stdout so you get some more info (but a real progress bar would be nice).
As for why git can't show you an accurate progress bar while fetching (specifically when using an extension like git-lfs or git-xet), this has to do with the way git extensions work -- each file gets "cleaned" by the extension through a Unix pipe, and the protocol for that is too simple to reflect progress information back to the user. In git-xet, we do write a percent-complete to stdout so you get some more info (but a real progress bar would be nice).