Issues upgrading Z540 from 32-bit Vista Home Premium to 32-bit Windows 7 Home Premium?

I have a Z540 (P8600, 3 GB RAM) running 32-bit Vista Home Premium, if "the vista drivers work for the most part", does that mean just doing the Upgrade Install to 32-bit Windows 7 Home Premium will result in a computer that retains the special functionality (stamina/speed, brightness controls, HDD protection, HDMI, S1/S2, eject button, docking station, etc) or will I still have to track down and install additional drivers (whether they be Vista or the nonexistent Windows 7 ones?) I would like to upgrade to Windows 7, but I'm pretty happy with the Vista set up I have currently (WEI of 4.4), and would rather not put the computer or its functionality at any sort of risk. Are there any known issues that the upgrade install to 32-bit Windows 7 has?

I've taken a look at many of the other threads on the forum, but they largely involve the 64-bit clean install as you said...and again I'm not willing to mess around with the BIOS, etc.

Is there any sort of campaign or movement to have Sony support Z owners who want to upgrade to Windows 7 (I would be willing to wait for that), or is it a lost cause? Has anyone found any sort of Sony or Microsoft support line that is all helpful for this issue?

BTW, can anyone comment on the extent of the performance gains or other benefits of going to Windows 7 32-bit from Vista 32-bit? I'd like to be able to conceptualize and quantify in terms of start up/shut down times, program start up and speed, etc. -- is there any head-to-head data for the Z?

Is the performance difference between 64-bit and 32-bit Windows 7 worth the effort, provided I'm only running 3 GB RAM and do not plan to add more?

Thanks!

 

can anyone help with this? anything would be greatly appreciated. thanks