There were 4 main problem I wanna to say here, ask people for help and discussion:
Heat: I think my computer is not configured correctly (hardware) or something else, but I checked the laptop and I was so hot! Using SpeedFan and they're all around 47-49 Celsius degrees, even max 63 Celsius degrees. Can Dell fix this problem? (Issue in next BIOS update?)
Display Issue: See this "http://whirlpool.net.au/wiki/?tag=Dell_Studio_1555" > "Issue" > "Color Issue". I wonder if it's fixed in BIOS A08 update yet?
Graphic Performance: ATI Mobility Radeon HD 4570 said to be support DirectX 10.1 (with Pixel Shader 4.1). But I think it didn't. I tried on some DirectX 10-games, it ran very slow and didn't have any DirectX 10 effect out there, also no shading. When I turned off, using DirectX 9, It ran very fast. Can someone explain this for me? (Evidence: test laptop with DirectX 10 test by using PassMark. It got an extremely disappointed score, slow performance)
Aesthetic : Many Dell programs still have old icons, they looked so unsuitably with Windows Vista/7 environment. Example: Dell Battery Meter in Power Options, QuickSet, System Software,...).
Update Delivery: Dell delivers updates very slow. I mean, I had to wait for nearly a year to get an updated version of ATI Mobility Radeon Driver, IDT Audio,...