Digital BW, The Print

Since receiving my 1280 last week (eBay purchase) I have been
experimenting with Paul's curves, and Clayton's guidelines for BO
printing, using UT2 inks.  On a lark I decided to try BO only
printing using the stock Epson black cartridge, and was surprised to
see that the results were really quite nice.  Are there any reasons (I
guess cost would be one) why using Epson black for BO printing is not
a good idea?  

Cheers,

Rem