I’ve tried a bunch of flats. Cobalts are cool for the sizzling round sound they are designed for; and Chromes always felt very vanilla to me on everything. LaBella LTFs and Sadowskys (made by LaBella to Sad specs) are the best two in between standard LaBellas / Fenders and Cobalts, to me. Rotosound 77s would be on the closer to round end, but not to Cobalts, to my ear.
If you want low tension, the LTFs are a no-brainer. If you want a little more, but not bridge cables (like 77s and heavier DTFs), the Sads are great.
If you want low tension, the LTFs are a no-brainer. If you want a little more, but not bridge cables (like 77s and heavier DTFs), the Sads are great.