Some people swear AccuRip has GREAT customer support, but I am agreeing with Dan here - unless it is super obvious, they almost always assume the error has nothing to do with their product (which is only SOMETIMES the case).
I have only used AccuRip, once we get it going for each computer/OS/printer/output art program, it's totally fine, but changing any one of those 4 variable WILL lead to some frustrations.
When working, the control variables (outside of the RIP work itself) we enjoy are:
control over printing from any number/combination of ink sources (we print from ONE)
control over linerization (sp?)
dot control (only changed if the INK brand is changed)
resolution (allows "acceptable and fast" printing as well as "slow and fantastic" printing)
Having never had another RIP i don't know if that is winning or losing. It is a pain to get setup, but when the combo is working, it's pretty much set it and forget it.