I've had LaBella flats on my Curtis Novak pickup-equipped MIJ Fender VI for about 12 hours now.
Single & multiple note articulation in the mid & upper portions of the register sounds like a big, sweet jazz guitar, and low register notes sound like those heard on a short-scale electric bass.
Aside from also making my 'VI sound tie-dyed 'vintage', there's no longer any fingernails-on-a-chalkboard round-wound string squeaks when glissing about all over the neck. Smooth, man. Smooooth...
Also the LaBella flats have a very even (but not perfect) tension across all six strings.
As well, the E 1st can be bent to produce a semi-tone pitch increase before the string jumps off the Mustang guitar string saddles which the MIJ (and '70's I believe) Fender VI's are equipped with.
Selective saddle-shimming or the use of saddles which are individually height-adjustable could be used to combat this well-known tendency.
I will be buying more LaBella flat-wounds for the Fender VI from Elderly Instruments due to their low ($40 per set) prices:
http://www.elderly.com/accessories/n...set--7676F.htm
Hellcat VI players may wish to check Elderly's site once LaBella flats for the 'Cat are shipping.