Some math can tell you it's significant
4.08 bore = circumference of 12.82 inches, multiply that by the two heights to give surface area
12.82 x .06259 = .8020 square inches
12.82 X .05905 = .7570 square inches
Right off the bat, the surface area difference is 5.6% greater for a single ring, and assuming the same material, finish, and pressure, would alone be significant, but there are two, although the second ring usually has significantly less surface area. And overall, ring surfaces are not flat so that's a bit of example math more than actual math, but it does make a difference
However, with 5% less area on that ONE ring, never mind 2 compression rings, you need less pressure to provide the same ring seal, so you end up dropping drag in two ways.
Now that being said, nothing wrong with a 1/16 3/16 combo, but 1.5 is better, and 1.0 works even better when you can and 1.0 can be more forgiving than a larger surface area ring as well.
12.82 X .03937 = .504 sq inches, for a 1.0mm now we are talking a bunch less
Hard to beat the new stuff since the materials got better.
All that being said, if you were stuck with a 1/16 ring because of the piston you wanted, and you were willing to pay a premium for those new gas ported rings, I say go for it. I considered it for an upcoming build I am doing with a specific piston, but decided the gains would likely be better spending the extra 130 bucks elsewhere and use a standard premium ring pack (just good rings)
As far as numbers, I would say as a guess, the 1.5 3.0 combo depending on build is likely worth 5-10 HP more as bore goes bigger, there are some SBC tests out there, and the 1 mm / 2 mm maybe 5-10 additional, again, depending on bore size, not big numbers, but if you can get a quality piston with a 1.5/3.0 and then save 100 bucks on rings, better than going old school ring size and paying your way back to the 5-10 hp that the metric gets you.
Now, let me tell you what they FEEL like, all std tension
1 - old 5/64s, you use a rubber mallet handle or nylon beater to put a piston in a cylinder and get to position
2 - 1/16, same thing but you can use a tapered compressor, it just takes a good shove and then less tap to move after
3 - 1.5/3.0 - you pop pistons in with your thumbs and they easily slide down to the crank journal pushing with your fingers
4 - 1.0/2.0 - they almost go in like no ring, and almost feel like they will fall to the crank journal
It's dramatically different drag