The draft of the Cal is listed as 4' 9", compared with 5' 7" for the
O'Day. Would this make it somewhat more tender,
YES and prone to "pirouet" out of a hard-on-the-wind beat, also would
be more easilly broached. Although the VCG (vertical center of gravity)
is not listed, I certainly do a coarse roll period test on both: just
rock the boat back on forth and measure the roll oscilations per unit
time. http://www.image-ination.com/sailcalc.html
but perhaps faster
under light winds?
YES but wont point as well as the ODay.

More questionable for blue water cruising?
Since the capsize ratio is near 2.0 on both boats, neither would be a
good blue water boat but sind the Oday has a broader beam (11.8) would
have better dynamic stability. The Cal being a shoal draft with narrow
beam would not be a good stable platform and would be more prone to
roll over/capsize in overwhelming conditions.

These are nearly identical boats (by the 'numbers') and the D/LWL value
of the Oday will make her accelerate a bit faster ... a good thing if
you sail in mostly light winds.