Kylin is, at minimum a 94-97 4*. Akers is, at most, a 97, and I really don't think he should be ranked any higher than Kylin at all based on where they are today. Wasn't impressed by Akers vision at all, while he certainly has the other tools.
Thompson is a 96+. I don't buy that, as of today, there is a clearly better dual threat QB in the country coming out of HS -- and the fact that he's going to play for the CFB QB whisperer should add another 1-2 points to that, so these services don't "Dak/Fitz" themselves -- AGAIN.
Brennan is a mid-level 3*. He's Dylan Favre with height, far less escapability, and no off-field issues I'm aware of.
I don't really care where the rankings end up having them -- but that's the reality of the matter according to my "untrained" eyes.