Just saw an early screening. Overall I feel pretty meh about it. I will save spoilers until its official release, but here are my spoiler free thoughts:
Quality wise, it's as bad or good as every other Post T2 sequel. Does it come anywhere near the quality or satisfaction of the first two? Absolutely not.
Dark Fate is serviceable at best, but ultimately generic and unnecessary. Story wise, this is all very familiar ground. We've been down this same old road multiple times at this point and its very tired material.
The action was making me dizzy. Felt like I was watching a Transformers movie where everything was cranked up to 11 and was so over the top I could not suspend my disbelief at all what so ever. There is zero subtlety and zero suspense. Its like getting hit in the face with a fire hose for 2 hours.
Music means a lot to me and T2's music was truly excellent, and the musical cues and themes meshed so perfectly with the film. T1's music is dated, sure, but works well with the film. The music here is so utterly generic and just there.
Is it terrible? No, but its certainly not great and I would not recommend going to see this in the theater. When its available on streaming and if you are bored one night, its worth throwing on, but nothing worth going out of your way to see.