I've got a Dell C1760NW printer and wasn't willing to pay hundreds of pounds for genuine replacement toners. These are full compatible and worked instantly upon installing them.
I compared print quality between the original cartridges and these and there is no noticeable difference in quality. I haven't made it through a full cartridge yet but I'm estimating that I'll get around 1000 sheets out of the black.
Most of the complaints about the cartridges are the result of users simply not reading the manual. Cartridge Detached errors, compatibility errors, etc; are mostly the result of not changing the settings in the printer. Read pages 92.97,113 & 119 of the manual and act on the advice to change the setting to using non-Dell toner cartridges before complaining about incompatibility. I've used a couple of packs of these cartridges so far and not encountered any problems. Number of pages you get from a new toner cartridge? They are about the same as the Dell cartridges but a fraction of the price. It's impossible to quantify exactly because it depends on what's on each page. Even if you only got 2/3s the number of pages as from a Dell original it would still represent excellent comparative value for money. As for not getting as good a colour reproduction as from the original Dell cartridges? Unless you are calibrating your laser printer the same way that photographers calibrate ours with an expensive colorimeter, I don't know how it's possible to tell for sure and it has to be a subjective opinion - unless of course the user hasn't read the flipping manual and changed the settings as per the instructions (?) I don't detect any real difference in colour quality and guess that the same dyes are used in the toner cartridges as in the Dell ones as there are few toner powder manufacturers in the world.
I have no information about long-term use yet but I can confirm I installed the set in a Dell C1765nfw with no problems at all.
Sequence - turn printer off, remove one old cartridge at a time - with the new ones I gave them a shake first then used the same gripping points as I had used to remove the old ones. I took off the tape covering the place where the toner comes out (a sort of blunt nozzle) as I figured that would tend to stop it from dispensing toner when called upon. The carts are not all the same size and shape but all fit pretty easy. Just make sure the latch clicks to hold them in place.
Closed the door, turned the printer back on. It chuntered around calibrating for a couple of minutes then it reported four full carts. Printed a test pic and I couldn't tell any difference.
Notes - this is with Windows 7, the printer is on a USB - don't need the hassles of wireless printing - and I didn't do any custom settings. Just banged the printer on the end of a USB cable when it arrived and set it as default.
So no comments about long term use but this is a set of four that combined cost roughly half the price of a Dell Yellow cart. So any sort of reasonable longevity makes it a good deal
There seemed to be lots of problems from other people, but at such a low price I thought it was worth the risk. Installed them all gradually as they ran out in my Dell C1760nw printer and although I had problems at first I consulted the manual and went into the printer settings and selected the option "Non-Dell Toner Installed." Now they work absolutely fine, although you don't get the visual display from the printer web page showing how much is left in them. I think this is probably the disadvantage of an unofficial toner.
I would recommend reading your printer manual and making sure you have this option available before purchasing.
This product is terrible - Don't buy!!! They do not work with me Dell 1350cnw!
I bought them in September but only started using them in October. As my toners ran out I gradually swapped in the these new toners and over the last few weeks the printers spends ages trying to locate the new toners, there is s a lot of noise from the printer, half the time it won't print any documents and when it does the print quality was really faded. I have tried to reinstall them, looked at trouble shooting on the Dell website, looked at all options and I finally replaced the toners and the printer is working better again. I am concerned these toners have ruined the quality of print as although the printer now works....it is not to the same standard. So disappointed with this purchase.