Miki's, I would give a solid 7. The tracks are okay for the most part. The new arrange of catch you catch me was interesting. Takanaru sounded weak from the preview, but I ended up liking it.
But Miki's version of Kyun has always been my least favorite so that track was... Eh. The "Happy end ni shite" part in the middle was particularly painful. If it were up to me I would have given Takane Kyun and Miki KisS lol.
They changed the arrange for Futatsu no Tsuki up a bit, but I actually kind of like it better? There's like a funky guitar thing during the "ochiyuku yami ni" part that's featured in game.
Destiny -Taiyou no Hana- ended up being really disappointing, especially since it was a cover I was hyped for. She sounds really exhausted :/
Tldr both of them are pretty solid. There are some parts I'll bellyache about because that's what I do, but there are some surprisingly good parts too.
(I saw Takane's 99 Nights on tumblr and did a little digging and found the mp3s. I'm as surprised as you are that they're out so early. Every CG anime cd so far has broken its street date, so it's probably the same party leaking these before the official release lol)