I use a steahly. I'm sure it's all a matter of personal preference in whether it's useful or not.
With a brand new 756 finding traction isn't a given...depending on what I happen to be in (ever ridden on dry decomposed granite? Good luck getting ANY traction.)
Slowing down rev uptake? Not a whole lot. Some, yeah..but that aids in keeping wheelspin down.
What I find to be a BIG help is it's much easier to keep the bike running on a long downhill. It's no longer true that a touch of the rear brake with ANY clutch still 'on' will kill the bike. You have much more control on a downhill if your engine is running.
But then, downhill 'round here means going down stuff you would have a hard time STANDING on. Maybe that doesn't apply to what you ride in.
Much better front end control, too. Tends to skim over junk (ruts, roots, branches, logs) better. Another 'less wheelspin' thing..which means more power applied.
Combined with the RB mod, you can be one-up gearwise (lever..not ratio) and still have the power to pick the front end up anytime you want.
I recommend buying some different bolts for the mounting tool. Get some (they are 1/4-20s) longer ones that still have a shoulder..threads NOT all the way up. Cut them so you can SEAT the bolts in the weight but not touch the flywheel. That keeps them from slopping around in the threads of the weight, so you won't tear up anything during the install/take-off process.
Besides...chuck needs the money! Sending a couple bikes to spain for an ISDE ain't cheep! :)
(As foghorn leghorn would say, 'thassa joke, son.')