EXS 24 Logic Sampler Users Group

I've used akai samplers for years and the amp envelope is ADSR with values
0-99 it is childsplay to use. And I always like to sharpen drum samples with
decay etc.
I can't work out how to set individual decays with the exs. The 50% up and
down thing doesn't seem to be able to set an individual group to zero
sustain and changeable decay.
I also don't like the ms decay setting. It starts from zero decay and then
opens up sloowly. All I want is a simple akai style decay that starts from
fully open. Starting from zero decay makes no sense to me.
Am I just using it wrong?