QTR-Quadtone RIP

Hi all, thanks for your help so far. Is the newest Epson print head  
technology in the 3800 better enough to not get a used 4000? I have  
an R800 and am thinking about the 2400 or something bigger to use  
with Peizotone K7 inks to print my rocks and trees. Where do you see  
Epson going from here?

Thanks,

Dave Polcyn