TigerDirect version is OEM. No support from Microsoft if you have issues (but that's what we're here for).
Amazon version is full retail which includes technical support from Microsoft.
Additionally, the OEM version is tied to the motherboard. Barring motherboard failure (technically), you cannot install this OS onto another system.
I *think* both retail and OEM have both 32 and 64 bit, but your only concern would be the 64-bit. Note: If you install the 64-bit version onto a system, you cannot also install the 32-bit version onto another system at the same time.
The cheaper one is the OEM version which ties you to your motherboard. If you have to replace your motherboard, you will have problems re-installing Windows.
This version also does not allow you to get support from Microsoft as it is the System Builder version. You may also have some problems with reactivations when you reinstall on the same motherboard after some reinstalls...I think they say 10.
The more expensive one is the full retail version without any restrictions to the motherboard or reinstalls.
My main concern with win 8 is the fact that some of the software im going to use is not compatible (yet) with it.
The start menu is also quite annoying.
''Do you have an old Windows operating system that is not installed on any other computer? ''
if you have software that could instal on Vista or Win 7 then it will install on Windows 8
Possibly in compatibility mode but often it just instals
Thats been my experience so far
The lack of start menu is annoying at first . I did try adding one and it was Ok , but now Im using it as shipped .
You quickly learn to think of metro as a start menu for programs you have installed , and you can pin those you use frequntly to the task bar . For all the other windows programs you might want then mouse to the top right and click search . Too easy .
Turning it off is the hardest part , and its always two clicks slower to do that than any previous version of windows .
Mine installed on a samsung 830 SSD and from cold boot to desktop is about 7 seconds . From sleep its more like 3 which is a lot faster than Win7 would be