I have been using them to print old technical manuals, such as the CP/M ones (went with A5), the Colour Maximite 2 manuals (A5) and also more recently for Norman's Assembler course (A4, colour) and just yesterday I received the SMSQ/E manual (A4)
In every case the printing has been top notch, although it can only be as good as the quality of the source PDF of course - some CP/M manuals have that authentic daisy wheel printer look

As an example, the SMSQ/E manual I got in black and white A4, ring bound with clear plastic covers front and rear, all for £11. I reckon that's pretty good. I treated myself to colour for Norman's book since it is used so extensively throughout, and I am glad that I did. Note that colour pushes the price up very significantly.
Delivery is usually within 3 days, and they always include a chewy sweet too, for those partial to such things (I don't, but my wife is a fan)!
The website is really very well done and easy to use, which is not the case for a lot of business sites these days.
I thought that the above may be of use to anyone else wishing to print off any manuals from eg Dilwyn's site's documentation section.
Disclaimer: I am not affiliated with the above and of course your experience may not match mine - don't come knocking on my door if you send off some PDFs of the QPTR system and get back a set of instructions for de-worming cats...
