you say youve always been using a ciss, why would you consider changing?
are you happy with what your getting with compatible inks? if so, there is no mandate that states original inks have be used, or anything like that.
as long as the inks you buy are good inks, no reason to change them
only issue with running a ciss is it increases the need for profiling - not an issue if your prepared to do your own color management, but thats up to you
Jan
If you are new to printing, I would start by using the printers own inks. Why ? It removes one significant variable. printing your own work is fun and very rewarding, however for quality it does require a bit more than pressing the print button.
As far as colour management is concerned, I've included a link to more information.
http://www.luminous-landscape.com/tutorials/understanding-series/und-print-mgmt.shtml