Digital BW, The Print

I've been having great fun with the r220, and I'm ready to upgrade to the 2200 or r2400 so I 
can make larger prints.  I can get a refurbished 2200 for $450, and the r2400 goes for $800 
or so.  I plan on using both of them for B&W output, and if I got the 2200 I would also buy 
the MIS inks (about $100) and QTR ($50).  So when I add those variables, the price difference 
really comes out to about $200.

What are the other main differences between the 2200 and r2400?  I know the K3 inks are 
more archival than the inks in the 2200, but I will be using the MIS inks in the 2200 so I'm 
not sure how much of an issue that is.

Thanks for your help,
Chris