All the features of the Ultimate version I did not need, the possibility of data backup on the system and the Remote Desktop host for purchasing the product instead of the home version. Only because of the XP mode, I would have not bought the Pro version, which I had already tested the RC and was not very impressed in terms of speed.
In recent weeks, I had several times by Norton Ghost images between new "patch" XP Media Center, Vista Ultimate (both 32-bit) and Windows 7 RC (64-bit) back and hergewechselt to even over long periods of time, the functionality, stability and speed to learn over and over again.
Windows 7 was the system that was my favorite part. At least on my PC it runs incredibly fast compared to Vista (as usual grotto lame) and also faster than XP MCE. The many little things in the enhanced user interface are compared to Vista also a plus.
What irritated me a bit in the Pro version of Windows 7 was the supposed absence of all games - but after a short search on the Internet turned out that these are only not initially installed, but on "Control Panel-> Programs and Features-> Windows enable or disable functions "in the list of available software to be subsequently activated (I had to call anyway to enable the Telnet Client - under XP is the active, since Vista you have to recharge it first).
Unfortunately "> Local Security Policy System and Security-> Administrative Tools-" in the Security Options of Local Policies in network security is also in the Pro version in the range: LAN Manager authentication level, the value is undefined. Who has trouble accessing shares of other resources (some NAS or Apple Time Capsule), there should choose a meaningful entry (eg LM and NTLM responses Send, NTLMv2 session security). If you like CTRL + ALT + DEL key to unlock the application, is set in this area anyway entspreichenden the entry for the Interactive logon - here is the default setting "undefined".
These are just little things that only require some manual work and represent not unsolvable errors. Most users will probably not confronted with such a thing.
In general you have to Windows 7 really a blanket recommendation. I work with it just as gladly as with Snow Leopard on my Macbook Pro.
Windows 7 just makes a lot of fun and is a welcome - and looking back at the unspeakable Vista necessary - development. Had called it "Windows Salvation", it would not have surprised me.