I have had my canon cartridges re-filled there also and have had no problems
at all. You must remember that the cartridge world shops are franchises and
may not use the same ink. Seems to me 1/2 the rrp is not a bad price to pay
for re-filling your own cartridges along with a unconditional warranty on
the refilled cartridge as well as a warranty on your printer.
regards
Dave