Be careful -- I ordered these by mistake thinking it was the bundled XL pack. Only the black is the XL. Bought in April amd actually just put the last 951 color in a couple months ago. All 3 of the color cartridges are low on ink already. The combo pack usually lasts me for a year or more. The black is still fine -- so why would you even bundle the 950XL with non 951XL cartridges is beyond me. The ink itself is all that I will use in my HP printer and works fine.
I ran out of colored ink for our business printer and decided to stop by Staples on the way to the office. I was saddened when the store did not have what I was looking for and only offered the multiple pack including the black ink. I already have a good stock of black inks and would have preferred not to purchase another one. This may not be a big deal overall but with three different hangers which can hold multiple packs all were empty. I would still recommend Staples to people as their mail-order is always reliable.
I bought the HP 950XL/951 High Yield Black and Standard C/M/Y Color Ink Cartridges (C2P01FN) Combo 4/Pack by HP at my local Staples because it had a 40% return in bonus points in my Staples rewards account back in September and am hoping to see those points credited to my account soon as they have not yet been credited. As for the product I have used the HP cartridges for quite some time now. The advantages are that the system lets me know well in advance when the ink is getting low so one can purchase more cartridges. I doubt that refilled cartridges can have the same capability of early warning.