Quick note for anybody interested in buying this as a truly mobile machine: Finding reasonably priced batteries for the 17 inch Powerbook models is difficult. For unused batteries, you usually have to pay around 100 EUR or higher. (For comparison, you can buy brand new batteries for 15 inch Powerbooks for around 20 EUR.)

Having said this, the Powerbook 17 is a very interesting choice for desktop uses since it offers many advantages of G5 systems without the added noise and power consumption. Thanks to 128MB of graphics memory, you can use it more comfortably with higher resolutions and / or many screens than Mac Minis with either 32 or 64 of graphics memory. Powerbook models with 128MB of vmem also tend to have dual-link DVI ports so you can use modern 2560x1440 screens, which is another advantage compared to Mac Minis.

As long as you close the lid quickly after powering on the machine, it will operate just like a desktop machine and the internal display remains switched off during use.