Kevin Neave k wrote in message ...
The difference in height will be negligible.

Not true. A full load of water makes a HUGE difference in pullup
altitude gained

The glider's energy, both potential & kinetic is proportional
to Mass so the height gain for a given loss of velocity
will be the same.

Again, wrong - check your basic physics. You even say that the energy
is proportional to mass. Therefore, more mass, more energy, more
altitude gained. You appear to be confusing velocity with mass.

However the ballasted glider will have a better sink
rate at 100kts than the unballasted one so during the
few seconds of the pull-up it will 'lose' less height.

True, but the crossover point is quickly reached so this effect is
probably negligable.

On the other side of the equation the un-ballasted
glider will be able to pull up to a lower speed, so
it's change in velocity will be greater so the resulting
height gain may be more.

If you pull up below the ballasted sink rate crossover speed, sure a
heavy glider will gain less. But at those speeds neither glider will
gain much anyway. The real test is what you can gain at redline.

(My money - if I had any - would be on the un-ballasted
one)

Too bad, I love a sure thing!

Kirk Stant
LS6-b (which loves ballasted pullups!)