I'm starting to see people do covers. Not a lot, but some, that use the new SP voicebanks... honestly? Rin and Len are the only ones that sound okay, and even then they are still blown out of the water by their previously released versions...
Out of all of them? Luka and Meiko were absolutely MASSACARED. They level of disrespect these two queens got has only made their original, discontinued releases go up in value. Their SP "updates" are utter ASS.
Kaito just sounds... less muffled (ie. syllables are sharper). He's not as muffled as his V3 update. Other than that, he literally sounds the fucking same.
Miku? She sounds like she's reverted to a shitty pirated version of her V2 voicebank. Someone took really, really poor quality exports of her vocals and imported it into UTAU. That's what she sounds like. There's also no soul in her voice anymore.
Below are examples of each SP voicebank, from "best" to "worst".