I have a set of Flexocore Deluxe on my Seth Kimmel bass, which is set up for 100% orchestral playing. I love the G and D strings. The A is nice, but I wish the E was more responsive. I am going to try a Permanent E and possibly a Permanent A. I know that I'm just going to have to try it out since every string sounds different on every bass and under every bow, but I am wondering if I should have any concerns about mixing strings with different tensions. My main concern is having different tensions on different sides on the top.