Any thread that has asked for tool recommendations starting out or opinions on "must have" items I've always said. Impact swivel sockets are must have items first and foremost.
Being in the middle of the rust belt I rely on 1/2" drive stuff.
90 percent of tine I'm armed with an electric stubby gun and swivel impact sockets.
I have both Snap-on and MAC.
To your specific question of which one is best for transferring torque...
I've no idea and that's extremely hard to quantify an actual torque transfer or rather which one loses the least amount of torque.
I can tell you this much.... I only used Snap-on for a long time but I picked up a genuine MAC set a few months ago because im my world clearance is everything. MAC is much shorter than Snap-on. That little bit of difference can mean get on fastener or not at times.
Now, I only grab the MAC swivels because of the shorter size and my odds of not enough clearance all but went away.
You'll never rid the need for a ratchet or wrench completely but armed with a stubby gun, some short swivel sockets and maybe an extension or not, you can get nearly all tasks accomplished without needing anything else.
BUT...torque loss can still happen at times.
Just did a Silverado that someone went king kong style tightening caliper brackets. No swivel could remove those so I had to run a regular shallow impact straight off the anvil of a big electric gun.
Cost...
It's not very close. Snap-on is definitely the most expensive at around a cool grand for their metric set which is 10-24mm, includes 16mm (not used much) , but it skips on 20mm (no big deal), skips on 22mm (big deal)
MAC set is 13mm-24mm, skipping 16mm(not used much), 20mm (who cares),
but includes 21, 22 and 24mm which is a big deal. SO skips 22mm as I mentioned.
Both are USA
Cost......
Snap-on
shop.snapon.com
MAC
Mac-Drive™ design contacts flats of the fastener instead of corners—helps to remove fasteners with rounded edges, and prevent rounded edges from forming .Universal design provides a 30° working angle ideal for situtaions where straight on access to fastener is limited .Made from high-grade...
www.mactools.com
Good luck
I have both and use both.