I've been examining this for over 50 years. I'd explain, but then if I don't pass the "I did it with my own hands" my opinion has no value.
Just for fun, compare the 426 wedge and 427 BBC engines with similar bore and stroke but very different rod ratios. What factors are involved?

I have to question the value of long versus short simply because the dynamics change a lot from build to build due to many factors, and a comment made by Reher Morrison. They don't think it makes any difference. Maybe, maybe not. I suspect a lot of pertinent factors aren't taken into account.

a comment made by Reher Morrison
I read that, and (as written) it's completely wrong.
What they did not feel was necessary (but required for the statement to be useful) is that within the range of possible ratios (for a given deck height and stroke length) a change of .10" on a 6.00" rod produces no useful effects. Ratio changes below 5% (.30" in a 6.00" rod) are generally not useful unless the original is a bad choice (4.25" stroke with 5.70" rod). If the length's variable range were 1.00" the statement would never have been made.
Most of the "comparisons" done in magazines and on line change only the rod length (and piston CD to retain deck height). To make the A/B comparo valuable, other variables should be addressed (but were not), especially cam LSA and IVC. Short rods are more tolerant of late intake closing.

Let me guess: FAMOUS NAME beats actual engineering?

David Reher and Warren Johnson both state that rod ratio has minimal if any effect on horsepower production, obviously that is their observations of building and testing NHRA Prostock engines with very efficient cylinder heads and short deck heights.

I often hear of the importance of high rod ratios touted on here. Anyone have any comparison data showing a test between let's say a 4.25 stroke RB, one built with 6.700 rods and one with 7.100 rods where the only change was rod ratio and bob weight.
I'd like to see what impact it actually has.

With 452 heads, the longer rod wins.
With B1 heads, the shorter rod wins.

Wins with more peak power or just a smoother power curve?

So that being said, there are tons of 440-1 headed engines out there based on a 400 block with 4.25 stroke and a 6.535 rod (1.54 r/s ratio) that perform nicely.
Would these engines make a lot more power with a 6.800 rod?
What about in a RB block, would a 7.250 rod be a bad idea with 440-1 heads?

Let's examine a famous dead end: "de-stroking for more power". This actually worked when the only heads available were terrible.
When the heads improved, the shorter stroke required a longer rod to avoid high piston weight. So, as displacement (and vacuum) went down, the rod ratio went up, producing an engine with 1% higher peak power, and no torque.

The first question should be "how well does head flow match the existing package?".

I think the big differences were covered years ago in this thread and they haven't changed over time. Header choices, intake manifold options, bearing availability and crank choices are the big ones. Most of the other stuff doesn't matter much for the typical build. I've built a few of both and it seems like the RB engine goes together easier because more parts are available for it, but it is a little bigger and takes up a little more room.

Been running my low deck 470 stroker for many years w/a 413 forged crank and Chevy Eagle rods and stock main caps. Mid/upper 9's 1.33 best 60 foot and drive the hell out of it......