Haven't tried Cobalts, but recently tried the new D'Addario NYXL's (carbon steel) on two of my non-Alembic electric guitars. Normally, I use regular old D'Addario 10's or 11's on all my non-jazz electric guitars.
Compared to those, the NYXL's do seem to retain their tone and intonation properties a little longer and your comment re: snappier and maybe a tad louder would apply as well - that's what made me think they might be similar.
Can't comment on their resistance to string breakage, 'cuz I seldom break strings, but they do seem to be a little more robust than a typical nickel string.
Downside = they cost about twice as much as regular guitar strings.