I'm completely switched over. Aside from my two linux servers, every machine I run is on Vista, and the OS isn't even finished yet. Since Beta 1 we've been asked to "Self Host" - to run Vista on our primary development and productivity machines. On early Beta 1 builds, the stability wasn't so good, and the driver support was worse. Self hosting was a chore that I dreaded. It sometimes seemed like the decision was between productivity and self hosting. The Beta 2 platform was stable enough to work, but performance wasn't that good. Still, I kept filing bugs and the platform got better.
My advice to anybody using a beta product: File bugs as early and often as possible against anything that bothers or annoys you. If you intend to use the product long-term, it pays to have your personal pain points be addressed.
So here we are at RC1. I've finally upgraded my last holdout Windows box yesterday, and am XP free. There are still some nagging UI bugs and the occasional functionality glitch, but in the age of internet patches, updates, and hotfixes, the OS is release quality. Yet we've got one more milestone to fix bugs. I'm sold, and the following is a couple of reasons why.
I like the new development features. I'm a developer, so I suppose I would. The new development features like new APIs, rewritten audio and network stacks, and the DWM make possible program scenarios that just aren't possible anywhere else, most of which haven't even been envisioned yet. A lot of these are hinted at by blogs on this site. Unfortunately, if you're not a developer, you'll have to wait a few years before software catches up, but such is the way with new platform features. Trust me, it's nice.
The new integrated features are handy. Until I started using it, I never realized how much I use integrated desktop search. I can finally author and burn CDs and DVDs from explorer (sadly, no .ISOs). Per-app volume controls are very useful.
If you only wanted one reason for upgrading, it would be the security. The more obvious security features are probably UAC, Windows Defender, and IE-low. Each of these single-handedly obsoletes whole classes of malware. The less obvious ones are infused into every OS component. This is the first Microsoft consumer OS to be released with every single line of code vetted for security before and during each coding cycle. These are the threat models that Larry Osterman talks about. XPSP2 was a big improvement over XP Gold, and Vista is far more.
Vista now sells 32-bit and 64-bit versions right next to eachother. Moving to a 64-bit OS is inevitable, so this is an important step. Especially since my next machine will be 64-bit. Now, if only 3rd-party apps would start compiling for the 64-bit platform.
Oh, and Aero Glass? Very shiny. Much eye candy. Beautiful, if you have it. Also, not really necessary. A lot of electronic ink has been spilled over having to buy new video hardware just to run Vista, but it's not true. I'm typing this on a notebook with an integrated Intel 915 Express, which, as of this writing, does not have a WDDM driver, and my experience isn't lessened. Oh, it's nice to have Glass, and it will probably become necessary in the future as more apps support it, but anybody that tells you that you have to upgrade now to the newest video card doesn't have all the facts.
Overall, I only really need the following reason for running Vista. I have to use a Windows machine. And even in its non-complete state, Windows Vista is the best Windows ever released. It's better than 2k, 9x, and Srv2003. And it's better than XP. I can't wait until release. My name is Ryan, and I'm a Windows Vista user.