I have a set of these new strings on my Nash P63 and these flats are truly amazing.
Their feel under the finger is excellent. They feel good, glassy smooth. In that aspect they remind me of the LaBella.
Tension is on the elevated side of things, way more than Thomastik, higher than Ernie Ball Flatwound Group II and lower than LaBellas. At first they felt a little firm but my hands got used to them. Tone wise they are really interesting. They take EQ really well so they can be bright or can be really bassy thudy if you want to go that route.
I like them pretty well played solo but I started loving them as I discovered how they sit in the mix!
Flatwound can be a bit handicapped in a mix, they support the mix more than they stand out. These actually stand out and really work well. I was very impressed and even surprised by that.
I have been playing Ernie Ball Flatwound group II and group III for several years and I adopted them as my go to string after trying pretty much every flat I could put my hands on. I love their warm sound and tension. I must say that the Dunlop have been growing on me ever since I started playing them and they are a serious challenger to my old favorites. As aforementioned, their strength is tonal range, feel and stand out character in the mix.
It's too early to tell how they will break in but I don't think they will undergo as much change as some strings which start really bright and go really dull. These seem to be more even through this change.
I have been playing the Dunlop Nickel Wound bass strings for some time and enjoy them. These new strings consolidate Dunlop as a serious player in the realm of bass strings.