Overall I have been very pleased with the Primera Z1. It is quick and simple to use. I've been pleased with the results.
Unlike another reviewer, I have not found the slight jaggedness in text a problem and didn't even notice it at all until after I read his review -- I had to look closely to notice it. I have not tried to print graphics so I can't comment on that. I found the Primera Z1 extremely easy to set up: just connect it to my USB port, install the software (which was a snap), and follow the instructions to install the printer cartridge. I was up and running very quickly. It is true there is no printer cartridge indicator of how much is left, but then few printers I've used (and I've used many) provide that information which is why I always keep a spare cartridge. So this isn't a problem for me.
I've been using the Primera Z1 to label DVD discs and have used TDK DVD-R discs which have a silver satin finish and the TDK name, type of disc, size, etc. imprinted. (I had a supply of these prior to my purchase of the Primera Z1 and wanted to use them up before getting the plain discs which are recommended.) You can line up the disc in the printer and enter the text in the software so it won't overwrite any disc imprint (hint: if using imprinted discs, make sure the disc is in the printer so that the imprinted text runs horizontally).
I've used a variety of fonts with this in sizes from 12 points (anything smaller would be hard to read) up to 36 points and have been very happy with the results. I've only used a black cartridge. This sure beats hand writing titles in indelible ink or trying to use labels (which made one DVD I recorded of camcord film I had unreadable on my player).
The Primera Z1 is not going to give you the type of very high quality output you find on pre-recorded DVD or music CD discs. But if your needs, as mine were, are simple -- printing text directly onto DVDs or CDs -- it is great. As mentioned above, you can print in whatever font you have on your computer in whatever size (just highlight the text and then select the font from the pull-down menu, then select the size). You can mix it up, i.e. I had 3 different titles and printed each in a different font and size. You can have text centered, flush right or flush left, and justified. Also you can bold, italicize, or underline text. It will even do square bullets or numbering.
I probably should mention that I'm running this on Windows XP home edition.