The Mikoyan MFI vs. the Sukhoi S-37 have been discussed here quite extensively.
The 701 hasn't but I am aware of it.
I have seen the information on the other "upgraded' versions also.

Of all the Russian fighters that I, IMHO, would be most likely to pay any heed to would be the Su-30MKI's.
I am very partial to this aircraft, though I am partial to Sukhois anyhow.
Wonderful aircraft and quite deadly, though I do not tend or lean towards over-hyping the abilities of this aircraft verses 'others'. None-the-less, the Su-30MKI is probably the best production fighter the Russian Air Force currently has in service. Again, just my opinion.



regards
seekerof