The W520 is arguably the most powerful laptop in its class and is still extremely portable due to its 15" formfactor. This W520 is equipped with an i7 2720QM which is has a 2.20 GHz base clock with 8 threads and a turbo boost speed of 3.20 GHz. The graphics card is a Nvidia Quadro 1000M with 2048 MB of video RAM and is perfect for workstation applications such as AutoCAD while also being easily capable of playing the latest games in full HD. The screen is a matte finish 15.6" display and has a resolution of 1920 by 1080 pixels (Full HD). Colors are clear, vibrant and are accurate to make for better photo and video editing. On top of the screen is a 720p webcam which works brilliantly with the two internal microphones for video conferencing and VoIP. Hard drive space is also plentiful with a fast 7200 RPM 500GB drive and backups are easy too with the internal DVD writer. Even with all this hardware the W520 has a very good cooling system and never gets hot or overly noisy even when under load for long periods of time. The Lenovo W520 is packed with other useful features like USB 3.0, a fingerprint reader, and a trackpoint system.

Tech Specs (I cannot post the complete list due to TradeMe character limits)
Intel i7 2820QM
Nvidia Quadro 1000M 2GB VRAM
8GB DDR3-1333
500GB 7200RPM Hard Drive
15.6" Full HD display (1920x1080p)
DVD Burner
Wireless 802.11a/b/g/n + Bluetooth 3.0
USB 3.0, 4 in 1 card reader, eSATA, 720p webcam
9 cell battery (10.7 hours)

I own one of these laptops myself and I much prefer it over the Dell Precision or the HP Elitebook as it seems faster and better built. The laptop is covered by a complete warranty and I have heard support is very good, but I have never had any issues with mine. Similar configurations of this Lenovo regularly retail at well over $5000. Comment if you have any questions and I will do my best to answer them!