Had the same question, so I'd actually like to ressurect this one. My Fellers rep is really pushing Triangle of late, and says that it's a seamless changeover and prints just as well. I'm just nervous about changing anything involving a machine that costs more than my car - namely a VP540 and an SP300.
He did send me a link to a federal ruling that says that voiding a waranty due to use of third party ink cartridges is a violation of antitrust laws (
http://www.ftc.gov/bcp/conline/pubs/...s/warranty.htm) so that at least is nice.
Any positive or negative comments on Triangle Ink 
