Steve,

I agree that the sleeve dipole, coax-based J, and whip with radials
should all have the same radiation pattern, but I get the impression
that performance might vary quite a bit (specifically the impedance
matching?).

As far as increasing height goes, I agree, the thinner antennas will be
easier to raise than the version with radials.

Thanks all for helping me think this through. Now I need to do some
testing.