Shadows of Rose: One buying the Winters' Expansion is almost assuredly buying it for this brief campaign. The third person mode for Village was something I had mistakenly thought was merely given away as an update; but no, it's tied to this campaign's purchase (ridiculous). I only had it on for my rerun of Village for a few minutes before Ethan's rapid, jerking motions when running bothered me enough to go back to first person. So that's a dud.
New Mercenaries characters? I am not a fan of the scoring shooter gameplay, so I personally don't see the value in it. Maybe one day, but I doubt it.
For me, the $20 asking price is basically for this: Shadows of Rose. Is it worth it? No, not really. But the optimist in me will admit there is some value here, especially if you were a big fan of Village.

When we meet grown-up Rose in the end of Village, she only gets two minutes of screen time to develop a character. All we really get to see is that, like her father, she has a drive and will gladly fight her own battles. She's adequately admirable in that brief time, but not really enough to make me ask for her own DLC... but that's fine, as long as it's good?

Just like Ethan was in Village, Rose is done dirty here. If when you hear your character is going to be interacting with the “memories” of something and you immediately say to yourself, “Sounds like incoming reused assets to me,” then congratulations: we're equally prophetic. Rose only gets to explore Castle Dimitrescu, House Beneviento, and a bit of the Village. So we, the player, won't get any new sights through Rose. Pretty disappointing.
Her journey is a personal one where she learns about her father. It's not the most interesting thing in the world, and really the biggest highlight for me was Capcom continuing their running gag of doing whatever they can to make sure you never see Ethan's face.

Rose's powers are the only new thing you'll be doing gameplay-wise (from Village), and all she really has is a stun. It's nice to use in the first chunk of the DLC, the only chunk that really reminded me of “classic” Resident Evil in that you're not given much ammo and need to make the on-the-fly call of whether you're running past this enemy or burning your ammo killing them. While it's a retread of Castle Dimitrescu, which was already a retread of the Baker house, I enjoyed this portion the most.
The second chunk is House Beneviento again and, like the first time around, this offers the scariest moments in the DLC. I really enjoyed the “Let's play with dolls” segment, it was spooky and clever and ramped up in difficulty well.
It ends with yet another retread, this time of Village's Call of Duty-esque shootout ending, just thankfully not as insane and now toned down. The final boss fight is the exact same final boss fight from Village, only now you can actually dodge and counter. Rose gets a special power attack for just this fight and you'll use it three or four times. That was... alright. Might be better if I hadn't just played through Village, though.

It's over in two and a half hours (give or take, I really explored and wasted time) and like Ethan's mold-infested body, it isn't very fresh.
I don't know if Capcom plans to make RE9 with Rose as the main character, but if this DLC was supposed to hype me up for that prospect, it failed. I don't hate Rose or anything, but this largely felt uninspired and unnecessary. I wish Rose got something proper and this certainly isn't it.

I don't recommend Shadows of Rose. It's too expensive for an experience you've largely already had. It's not total junk, but is simply another disappointment when it comes to Resident Evil Village.