My first impressions are that several things have changed. There are fewer questions during installation, and it is faster to shut the machine down. On the other hand, the new user interface will seem scary to some people because it's so different, and I've found that there are more mouse-clicks and/or key presses required for certain operations.
For instance, Windows XP introduced the idea of user switching: this means that you can have two people logged into the same machine at the same time, and so a new person can log in while the first person leaves their applications running in the background. However, this only works in workgroup mode, not in a domain. In Windows Vista, this option does work for a domain too (as long as you have the appropriate edition of Vista to join to a domain in the first place), which is good. However, switching user requires you to press Ctrl+Alt+Del twice rather than just once, which is a bit tiresome.
The biggest problem so far has been compatibility, e.g. drivers and applications. This isn't really Microsoft's fault, and I think that a lot of these problems will be resolved by the time Vista is released to home users, but it's something to be aware of.
One strange quirk is that I have a SATA hard drive (rather than IDE), and I ran the Vista setup program from inside Windows XP to install Vista onto a different partition of the same drive (for dual boot). The setup program couldn't use the existing XP drivers, but I couldn't find any Vista drivers on the motherboard manufacturer website. When I inserted the floppy that came with the motherboard, the setup program was able to use the XP drivers from there, so I don't know what the difference is between them and the ones that were already in use, but I'm glad it worked. When I installed XP, I had to press F6 at the appropriate point in the setup process to give it alternate drivers for the hard drive, so I think that SATA may just generally be more complicated than IDE.
Aside from that, some equipment worked better than others:
- Sound card: I have a Soundblaster card (Audigy 2 Platinum Ex), and I'm using a beta version of the Vista driver from Creative, which will expire on Jan 8th (i.e. in a fortnight), so I hope that they release the official version or a new beta by then!
- Printer: I have an HP Deskjet 870 Cxi, and I got a signed Vista driver for this from the Windows Update site.
- Scanner: I have an HP ScanJet 5200C, and this doesn't have a Vista driver available yet. On the HP website, they say that they are planning to release drivers through Windows Update and their own site.
- Graphics card: I have a Radeon 9800XT, which was recognised by setup, i.e. the drivers are on the Vista DVD.
- Monitor: I have a Viewsonic VX924, but the Viewsonic website doesn't refer to Vista at all, so I'm using generic drivers for now, which work ok.
- Webcam: I have a Videum capture card from Winnov, but their driver page doesn't refer to Vista at all.
- Camera: I have a Kodak DC5000, but there aren't any Vista drivers for it, and support page says that the product has been discontinued, so I'm not expecting Kodak to release any. I think my best bet is to get one of those "N-in-1" USB card readers, and transfer the CompactFlash memory cards into that.
The CD burner and DVD-ROM drive seem to work ok, but there's a DVD (of Office 2007) which I burnt at work, and I can only access it through XP, not Vista. For now I'm sticking with Office 2003, to focus on the Windows changes.
I'm planning to get a laptop soon, but I want to wait until I can get one with an OEM copy of Vista pre-installed, partly to get around these issues. I've seen some laptops that offer free upgrades to Vista if you get one with XP now, such as Dell. However, there are a couple of potential catches here. Firstly, it may not be a completely free upgrade if they charge you for shipping/handling. Secondly, just because the machine is "Vista capable", i.e. it meets the relevant hardware requirements, that doesn't necessarily mean that all the drivers are available for it yet. If I bought a laptop with Vista pre-installed, and the sound didn't work, I think I'd be justified in saying "Oi! No!" (in the best tradition of Harry Enfield). By contrast, if I bought one with XP, then the manufacturer could probably weasel out of it by saying "Here's the Vista upgrade DVD, and there will be drivers for everything eventually."
There are also some issues with applications, which I think are related to the security improvements in Vista; specifically, UAC (User Access Control). For instance, Visual Studio 2005 is only supported with SP1 and the Vista update (beta version here, real version due in Q1 2007). Similarly, SQL 2005 is only supported with SP2; there's a CTP version out now, but the real version is again due in Q1 2007.
I haven't been able to install Adobe Reader v8 yet; I get an error saying that my temp folder may be out of space (which it isn't). I found some Usenet posts from other people with the same problem, so it may be related to the fact that I'm trying to install it onto my G drive (Vista) rather than my C drive (XP). There are a couple of potential workarounds, e.g. trying to copy all of the expanded files from the temp folder before I click OK on the error message box, but I haven't tried them out yet. For now, I think it's fair to say that Adobe need to do some more testing.
I've installed a couple of other applications (mIRC, Money) successfully, but I haven't tried them out yet. One issue for mIRC is that the help file is in the traditional format (.hlp file), which is no longer supported in Vista; applications need to use the new .chm format. (It may be possible to add support for old format help files via a separate download, but they're definitely not supported "out of the box".) The main mIRC help file is in the new format, but the FAQ is in the old format. As for Money, I'm currently using v2004. I didn't bother with the 2005 upgrade, and 2006/2007 are only available to US customers, apparently because there wasn't enough demand to justify producing a localised version (e.g. for different tax legislation), so I'm hoping that my current version will work ok.
Right now, the main issue I have is that my roaming profile doesn't work on Vista, so I get a temporary profile each time I log in as myself. I'm not quite sure why, so I'm investigating that at the moment. I think this is related to network protocols, since Vista uses dual IPv4 and IPv6 by default. I read something that suggested turning off IPv6, and that seemed reasonable since my server doesn't use that. However, when I did that I found that I could no longer see the shared folders on the server, so I had to turn it back on again. I've now enabled IPv6 on the server and on my XP partition, and I'll do some more reading up on the subject. On one level this is a nuisance, but on another level it's actually a good thing. When I encounter a problem like this, it means that by the time I've figured out how to fix it I'll have a much better understanding of how everything works; this will certainly be useful when I do the beta exam, as well as helping me to avoid embarrassing situations at work. (As a side note, Windows 2000 doesn't support IPv6, so a mixed 2000/XP/Vista/2003 environment could be tricky.)
Meanwhile, elvum mentioned that there are some issues related to the new content protection. I don't think they'll affect me personally, or any of the machines at work, but it's probably useful information for other people to be aware of.
All in all, my advice is not to do a big roll-out yet, and only put it on a spare machine or one with dual-boot. I'll be alternating between XP and Vista on my PC for now, but that does mean that I won't be on IRC for a while.