i tried to do halftones withe this epson 3000 and it won't.
i checked on screenprinters.net an article ( http://screenprinters.net/articles/index.php?art=45 ) that even an epson 3000 won't do halftones without a third party rip.
i bought the postcript model.
i also have a problem with this stylus rip, each time i try to print with it, i got a "command error #".
I haven't found a problem with Photoshop halftoning. So long as your dot pattern is set at the right angles for process printing, it should effectively do exactly what a postscript rip would do, only in pre-press form