I'm about done with the SE and OR global feats at this point, with a rigorous 4 battles a day schedule. SE was relatively fine as I was able to use them until S3 and early S4, as well as the DR/DM kill and stagger feats as side bonuses. OR was boring and grindy as hell. As Rath pointed out, it quickly becomes not worth the risk to try with the OR team. By 10/40 I had settled on the first Phoenix team in Sector 1 for the rest of that feat.
I guess what frustrates most of us about these grindy feats is that they are unnecessarily so. CG could have made it 30 wins, cut the rewards to 10 banners, and added some other global feats. It would not have made it any easier, but likely less repetitive.