The only time I've found a 1-9" twist to be "a bad thing" is when trying to use SPSX or Blitz bullets, the thin-skinned ones. If the bore is nice and smooth, no problems, but let it get some wear in it, and it will strip jackets to a fare-thee-well. Blue is a very pretty color, but I don't care to see it halfway to the target...........
I've owned 1-9" twist rifles that handled the Blitzes very well, and others that, brand new, wouldn't shoot them for beans. I like to use the SPSXs or Blitzes because of the price differences over the poly-tipped bullets, but that's the only real complaint I have with the fast-twist .223s.

You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.