Just a little recap on this post for those interested. Since this original post, I've spent a lot of time with LTF and ECB80 Chromes. I now keep the LTF on my rosewood 60s style Precision (PV63 pickup), and Chromes on my maple 70s style precision (EMG Geezer). There is some overlap, but there is also a lot of room for both to shine on their own, especially with different amp settings. They are my "dark" and "bright" basses, although the chromes can do dark well too. Both are absolutely perfect. And, in the end, I would actually put the LTFs a little bit stiffer than the Chromes. The Chromes take about 2 months to start shining, too, just be aware. But once they do, they give a brighter, dry, barking thump that is UNREAL. LTF is just a classic Labella string that sounds amazing on a rosewood Precision, you can't loose.
I also spent some time with 9050L on the maple bass, and I see no reason whatsoever to use those over Chromes. They are stiffer and more hollow/boring sounding. Harder to dig in, and less bite, growl, thump and bark than Chromes. But, of course, each bass/pickup is different.
I've been on a flats journey for years now. I've tried ALL of the more "flexible" options. It's my opinion that the above 2, along with TIs on a Jazz bass, are as good as it gets. I had TIs on the maple P for about 2 months, but they were just too loose for playing over the pickup. That's why on a Jazz played over the rear pickup where tension is higher, they are perfection.