oh i see somebody else was so kind posting his build.prop values for the mobile data issue. actually these are the ones i would recommend too in your case.
you may try to compare them with my deault ones and only change a subset of them. maybe this further increases your speed.
it is said that it is impossible to have one for all settings here. these settings depend on your local carrier and country. i obviously am using values as default ones fitting my situation :P
they should be perfect for europe at least.
anyhow, you may wanna play with the values. there is a thread on xda explaining a bit about them. you can safly experiment with them as the worst thing that could happen is that your mobile fails at all. though it can always be reverted back by editing them or reflashing the rom.
as already mentioned: changes to these values need you to reboot twice to take effect.
p.s. i'm glad you guys like my rom. as i see here are some new comers
i apologise that i currently won't be able to answer as fast as in the past. i am currently in the process of changing my job. finally i have to go into the world business, away from my current university position