Well I would like to first say that Fei is good, but needs to work hard versus some people.
Fei vs Guile is an example.
Fei needs to get in on Guile, but it is tough, becuz of Guiles low mk, and becuz of his recovery on booms. If Fei hop kicks over booms, he has to be careful that he does the hop kick right when Guile starts the boom or immediately afterward, because if he doesnt (except for full screen hop kicks with mk or hk over mp or fp booms), he may get a low forward when he recovers from the hopkick, or just get pushed back with another boom.
On top of that Fei also has to jump over booms to get close too, and one mis-timed jump can lead to a flashkick, that will allow Guile to set up pressure tactics like boom> jump>mk>land>lowjab>lowstrong/forward>boom and then things fafter that like sobat kick, or boom fakes and another flashkick.
If Fei does get in, and can get Guile into the corner, then he can do the Fei trap if guile does not have a charge, and/or he can rekka safely with the Fp,Fp,Lp rekkas for chip, and/or Fp,Fp,Wait, and if Guile does a boom, Fei can do the Fp,Fp,Fp rekkachain.
If anyone wants to add to this small amount of strategy listed for Fei versus Guile, please be my guest.
Next Opponent I will cover is Fei versus Cammy, whcih I really dont have too much experience with. I would love to hear what others have to add for this matchup. Perhaps after Cammy I will post on Dhalsim.