This looks like an old topic - but I'm a new member, so I will comment from my perspective. In the old days, I used to refill my cartridges (a black and a three-color combo cartridge for a HP 400 C (I think)). Never had any clogs. Invested in an Epson Photo Stylus 800 (also back in the day). For its time, it was a marvelous printer - but was prone to head clogs. I never, ever used anything but Epson inks in it . . . didn't help. Finally had to retire it because I could not unclog the heads.
That Epson 800 was a marvelous paper handler, could take really small bits of paper (like personal check forms). But it was subject to clogging. I should dig it out to see if it still works. Printed some great photos back then when most people in my crowd did not have the capability to do so.
Today, I own a Canon i850, i960, Epson RX380 and RX595. So far, nothing but OEM inks because I haven't taken the time to figure out how to refill them, and, I'm just not organized or preplanned enough to order from refillers online.
However, I have recently purchased a couple of expensive DSLR's, have many shots to print and want to print them. I signed on here to see how I might save on ink costs (and also trouble shoot a problem with my RX595 where it is leaving an intermittent smudge right smack in the middle of some of my prints - talk about waste!).
I will not hesitate to try refilled cartridges. To begin with, the Canon heads are replaceable - don't know what the cost, but they can be removed. Haven't explored how you clean them, but bet that I can find some info on that from this forum as well.
In the end, we should each proceed in the manner most comfortable to us.
Caruso