So Tempting, But What's the Catch?

This looks tempting but after over 10 years in the Apple camp, I am not sure *what* is good and what is bad. I do know roughly half the price of a 13" MacBook sounds mighty tempting....
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Compaq F579 (Refurbished) Notebook Pc,15.4"inch AMD Tuion 64x2 Dual-Core Mobile Technology TK-53,Windows®Vista Home Premium.
Hp: FRYS.com #: 5374688 Great Value Compaq F579WM -Refurbished -90 Days Factory Warranty Limit 1 per Household. (when purchased between 09/19/2007 and 09/21/2007) In stock, same day shipping Detailed Description |  Tell a friend| Warranty Info	larger view Price: $ 549.99
Detailed Description  [return to top] Microprocessor: 1.7GHz AMD Turion 64x2 Dual-Core Mobile Technology TK-53 Display:15.4"(1280x800) Wide Screen Memory:1024MB DDR2 Expandable T0 2048MB Hard Drive: 120GB 5400RPM Serial ATA Multimedia Drive: Multi-Format DVD-/+RW Double Layer Drive Conectivity: 56k modem v.90 ,Integrated 10/100 Network card Wireless Connectivity:802.11 b/g Graphics Card:NVIDIA GeForce Go 6150 (UMA) Shared Upto 287MB External Ports: 3 USB 2.0 ports for connecting a wide range of peripherals from digital cameras to MP3 players 1 VGA, 1 headphone jack, 1 microphone jack 1 ExpressCard/34 slot ,S-Video out Operating System:Genuine Windows® Vista Home Premium.