Soo... is there any reason to get this game if I already have DOA5 LR with plenty of DLC?
It is hard to say. If you didn't pre-order it's probably a good idea to wait until certain things are sorted out.
I can lay out the ups and downs as I see them:
Ups
+The game does look better, videos don't really do it justice. Sweat, dirt and bruises are all optional but make details stand out. Breast jiggling is still there, it's more natural but still overly exaggerated like you'd expect. Hair and costume parts don't clip through models as much anymore. Many outfits have destructible versions when hit by Break Blow
+Break Blow impact is good, especially when it shows facial animation
+The old post-KO trick to let the KO animation play out is back in Survival (post-match taunting, also Ryu can do d+P+K infinitely)
+There are a variety of new hitstun collapses called Fatal Stuns
+Danger Zones are as crazy as ever, some can be chained together
Downs
-Helena, Nyotengu and a few other faces got changed, some people may not like the difference
-Break Blows lack variety and the camera doesn't close up on Marie, Honoka or NiCO
-Match types other than Survival prevent you from doing anything during post-KO
-The grounded pain KO animations seem to be removed from the game entirely :(
-Some Danger Zones are so far away from the default stage positions you hardly ever see them, like the downstairs part of the museum
-Unlocking outfits is less challenging but also a lot more tedious. I've heard it may be redesigned at some point but right now it sucks
Neutral
Loser poses are still in, you can switch the focus to the loser with RB after the victory scene. But you don't get to see the full loser animation, just the looping part
NiCO isn't my taste, but I guess a lot of people like her since it seems like everyone uses her online
Really hoping the other unrevealed SNK character appeals to me, but it'll probably be Kula because they know I hate her