Just been playing the two LPs (and more!) to compare before I came on here.
They both have REALLY old strings on, I've been playing other guitars more recently, so not sure how fair this all is...
(Had a really good afternoon - I haven't played humbuckers much for ages - many thanks!

)
Guitar A: MUCH lighter, brighter acoustically, almost lacking in some bottom, but not horrid. Old Guards, more modern sounding, pushes the amp more.
Guitar B: MUCH heavier, more rounded and balanced acoustically. Stormies more vintage and open sounding, still rocks and bites when you want, but cleans up with pick attack and guitar volume much more pleasantly to my ear.
The bridge pickup of A is more biting and immediately "hey let's rock" - but some of that will be the guitar itself.
Guitar B doesn't rock any less for me, it's just that guitar A suggests it without asking, with B it's my decision (if that makes sense!!)
Interestingly, in this test the neck of B is "brighter" and breathes more - I suspect if the Old Guard was in here I would have too much bottom end for my taste... BUT new strings on both guitars would seriously improve both. In fact, I was already thinking I want to restring Lucy (guitar B) right now because I haven't really used her for a couple of years - when I got her she was WOWWWWWW... and when I got the next guitar I had to deliberately put Lucy down, otherwise I was never going to bond with the new one (and this was X guitars ago!)(at least 6, not counting acoustics or basses)
And then I got guitar C out... An SG with Riff Raffs in (strings just as old!). The bridge is more punchy and in yer face than both LPs. Neck goes well with it, but doesn't really do that plummy/buttery thing... and, this was a surprise, the neck is less bright/airy than both the LPs. And that's with the neck pickup position nearer to the bridge (and therefore getting a brighter sample from the strings than it would on a Les Paul). So, Old Guard and Stormy neck both clearer than a Riff Raff neck on these dead old strings.
And then guitar D (Telerocker will like this

) - I cleaned this up the other day, also has old strings, at the moment though - the 335 with Mules (these are unpotted). Acoustically, it is its own thing, but through the amp it's in the same ballpark as Lucy, guitar B, with her Stormies. They both are vintage rock, but the Mule bridge "kicks" a bit more for me. It's almost like the Stormies are more of a strat-player's humbucker, you work it a bit and it rocks, punches, squeals, bites. The Mule bridge needs less effort, and therefore maybe needs a lighter touch to get expressive? And it has that delicious Mule "hairyness" (a bit like the 57 fizz but actually pleasant!) - One or the other of Stormy or Mule will be someone's favourite and the other a very close second, but you won't know til you've tried both. The neck (and remember these are all guitars with old old strings - so not really fair) is up there with the Stormy for clarity and cleanup. They both do it real nice, but with slightly different character. My favourite is Stormies, but I wouldn't cry if you said I could only keep the Mules.
So, here's what I know you'll do

:
You're going to try Stormies because you already have Mules and, well, we need to get new stuff
You'll find an excuse to get an Old Guard as well, sooner or later


Now, changing pots... well, that's all personal preference, there is no right or wrong.
Yes, they will control sparkle, but... it depends how you play and what amps you use and and ...
This is what happened to me:
Lucy the LP with her Stormies. She's a 2012 Traditional. She has... wait for it... 300K pots in, and the volumes are linear!! Agh! the heresy!!

When I ordered the Stormies for her (my first set), I also ordered 500K CTS log and all that (I didn't actually know what was in there, I just thought "new"!!!)
I was so keen to try the Stormies, though, I swapped pickups without the new pots. It was SO good I've not touched the insides since - I still have the pots ready for if I need them elsewhere.
But I got to wondering "wow!! why does she sound so good and behave so well?"
And that's when I found that she has 300K, linear volume, and (I think) log tone.
Now, this SG, with her Riff Raffs. I'd never really bonded too well.
I was even wondering about getting her some Stormies instead (I have another SG with them).
And then I remembered... when I put the Riff Raffs in... I ripped out the circuit board thing and put new "500K CTS log" in just
because that's what everyone says.
Because Lucy was so good with the "wrong" electrics, I decided to check stuff out.
As an experiment, I found the old circuit board, ripped one of the volume pots off and found it was 300 linear... the lugs were a bit bent etc, but it was ok enough for a quick experiment, so I put it in the bridge volume position of the SG - WOWWOWOWOW!!
I immediately ordered a new set of 300s (2 linear, 2 log) for an SG...
I've since bonded with that SG and its Riff Raffs.
It's now my believe that it really is personal taste, 500s could improve a thing, 300s could improve a thing... you can do what you like per pickup per guitar.
If I get a guitar and it works, I leave it.
If I want brighter and it's got 300s, I change to 500s.
If it's a bit lary and it's got 500s, I change to 300s.
But I tend to lean towards what Gibson seems to think, "the old guitars had 300s in, so that's what we put in the reissue type stuff" (they may have changed since I read that).
Oh, and I use "modern wiring" (how the volumes and tones are connected) - I tried 50s wiring, and yes, more "sparkle", but I hate the way the volumes and tones interact. I've spent so long playing modern, that's how expect the guitar to behave, and I don't need any more air/sparkle, so I stick to modern.
By the way, my experience of putting 500s on the 57s or 57/57+ is... "time to change the pickups"

- for me it just brings out the 57 fizz that I think I can hear (I tried it on Guitar A before getting the Old Guards).