That is a tough one to answer. There are definite positives about recycled ink cartridges. They are - in theory - better for the environment. And they definitely are cheaper then buying new cartridges.
However, there are negatives associated with them too. Poor quality ink refills can cause print quality issues such as off colors and runny ink. They have also been known to damage print heads and other printer components.
When it comes to ink jet based printers, the money is made in the ink - not the printer. So if you buy and use ink refills and they damage your printer, then the cost of a new printer is often less then buying a whole new set of ink cartridges.
So in the end, I think its worth trying if you are looking to save some money and go green.