I don't see where anyone would want this if the car is driven on the street.
I did and I do. Love it. As an old guy with arthritic problems, I can no longer row a heavy clutch and 4 speed around.
There are a couple of "real" advantages for a MV body.
If this is a vehicle used in winter, like a pickup, and you get on a slippery place, you can drop it from 1 to 2 (or even 3 if you are careful) and use it to "kill" some torque enough to get going.
Having owned a horrid old Ford (the SKUD missile, a 78 LITD II) these transmissions, when placed in "2" were LOCKED in 2nd gear and this is a BIG help in winter, sometimes.
Likewise if you have a little "wild" in you and your engine, and you are trying to be "nice" near "someone who is watching you closely" 2nd gear can sometimes "ease" you away from a stoplight with shall we say, "more smoothness"
Hell, if you are just idling around downtown 25 mph traffic, you can just LEAVE it in 2nd.
"Did you know" that some taxis were set up that way? I think the theory was to avoid extra shifting in downtown traffic.