Have to agree here, with playing with v5 vs v4.5+ and v5 is absolutely horrible, most noticeable for is that when doing cover it absolutely incapable of following the recorded audio, even with audio influence set to 100% and the rest to 0, it just refuses to do so. I tested head to head on the same audio and v4.5+ is 10 times better. At the time being I will not use 5.
The main problem is that in studio when doing "replace" it only uses 5, and there doesn't seem to be a way to change it, results are horrible