The differences between 7 and Vista are a lot more diverse than many people realize. Vista is a resource hog and mainly because of it’s annoying unique ability of caching resources for a user’s “favorite” programs, leaving the system sluggish and unresponsive when running anything but those programs.
7 on the other hand retains this unique ability but instead of allocating the resources on startup as Vista does, it is far more flexible and only allocates said resources when said programs are actually initiated. Vista and 7 also split when it comes to compatibility. Vista does have a limited ability to emulate XP, especially in an X86 install. However compared to 7’s ability to actually run an entire XP subsystem underneath it’s primary, Vista looks like a child trying to comprehend physics. 7 Ultimate is able to run an XP VirtualMachine underneath 7 itself, allowing 7 to dynamically switch to it’s XP 32 bit subsystem on the fly when troubleshooting compatibility with old and outdated programs. Yes it is only available to those with Ultimate, however the advantages it provides is ridiculous, especially when using an X64 install.
Check here for more info, I’m not always the best at describing it, lack of words :P.
7 is also far more secure than Vista due to the differences in the kernel. Vista had a wide open kernel thanks to Norton, who sued MS when they couldn’t let their precious “antivirus” dig itself into the system. 7’s kernel is locked down and well protected, preventing programs from digging in without limiting beneficial programs abilities to add to the protection.
By far, the best version of 7 to go for is an X64 install, it doesn’t really matter whether you get Home (Basic or Premium), Professional, or Ultimate but go for the X64. The ability to address more than 4GB total system RAM; this includes your GPU, so if you have a 1GB+ video card, that’s 1GB+ of total system RAM already allocated before your actual physical RAM is taken into account, and take advantage of true multi-core performance when dealing with anything more than a dual core.
XP still has the edge in performance, yes but 7 is very flexible compared to Vista in that if you want a nice smooth performance boost on the fly, turn off Aero Glass and it’s effects and you can enjoy a nice smooth ride through Windows, and laptops around the world rejoice in the sudden increase in battery juice :D.