Don't know about Lenovo™ R400 but, do know plenty about the Thinkpad™ laptops running AutoCAD.
After numerous laptop PC's, I wouldn't shop another brand.
The IBM/Lenovo laptops rule!
Never a problem running AutoCAD '05 or '07 on these laptops.
Graphics Media Accelerators (GMAs) are intelligent and responsive graphics engines built into the chipset that is on the motherboard. This integration provides improved visual quality, faster graphics performance, and multiple display options. These GMA's also allow an integrated graphics machine to be built without a separate graphics card, which can reduce cost and streamline power consumption.
I like the 14" screens too, crystal clear, bright, easy on the eyes! Smaller business size, easy to transport.