I use them and mostly there fine. I have had one (eBay brought) which has been a PITA and one that was leaking constantly. I use more inks
http://www.moreinks.co.uk/Index.aspx now and have a great service/customer service and choose of budget and primer toners.
The quality seems the same as canon branded ones to me. After all you don't run a laser to print high quality photos. I purposely sort out a printer that had compatible toner carts available at lower prices with higher page yields.
Canon LBP5050n. Good printer, not a great printer but has network port, as good quality prints as I need (I print business cards/flyers/invoices etc), high page yield per cart, good priced carts original or compat and the printer was cheap. I know your not looking for a printer but this info may help someone.