For pickup and neck testing I have been using the Fender 8250s. Simply because they sounded good with the 1997 AmStd Precision I use for that kind of testing. I think I have to step this up a bit. The E string taper is annoying since it requires a saddle height adjustment on the target bass. I don't want any silk anywhere. And finally I think that strings with more treble would be better for this kind of thing. If there is no treble you wouldn't be able to tell what's changing in those regions as you mess with the bass. Think about the stupid debate about capacitors. Won't be able to insert facts into that one with round-core nickels. So I am thinking I will use non-tapered, non-silk, nickel plated steel roundwounds with hex core. Finally it wouldn't hurt if the strings were somewhat cheap and/or on sale regularly since they won't take well to being put on new basses regularly. I think the D'Addario XLs are the best best unless somebody has better ideas?