I have used HP printing products exclusively for years now and have never had any difficulties with ink quality. However I do find that like other users the cartridge tells you you're running low long before it's necessary. When it's really running out I experience gradual reduction in quality of the images I print out and often parts of the page printing will fade out so that you get blank sections of the page. However when this happens there is usually plenty of time to change the cartridge unless you're printing out an urgent job.

Personally I'm very happy with HP products and wouldn't use anything else for printing.

Another point to note is, as someone has remarked above, when your printer (mine is an HP Inkjet 1355 all-in-one)warns of low ink, it will in fact continue for some time without failing or even fading. But when it goes it goes suddenly! One page perfect next blank!