I like Feathers, but they always give me a little irritation, so I stick with Polsilver, Voshkod, Astra (Green), Derby and Gillette Silver Blue. I have some Permasharps coming to try. The next blades that I found very close to the Feathers were the Bolzano, the shave I get is almost identical to the Feathers including the weepers and irritation.

Never saw the Feathers in the blue packs, I have both the yellow and black packs (10's and 5's).

I too get about 7 shaves out of a Feather and the sweet spot for me is 4-6.