Not having problem with V11 64 bit.. running Win 7 64 bit on a i5-750 .. Using mostly AVCHD media .. I'd say on a new machine it would be worth trying V11 .. Just my 2 cents.

Save the image of the "out-of-the-box" system with GHOST 15 or Acronis. With this image, you can start over no matter which Vegas version you choose.

It would serve no purpose for me to tell you what I do (did) 'cause I can reverse my choice in a few minutes. I have and I will again.

I second what john_dennis said. In addition, I always partition my drive as soon as I get a new computer. For XP, I give about 10 GB to the C: drive, and put everything else on another partition. For Win7, I set up C: for 40 GB, although I could make that smaller.

Then, I use Acronis Trueimage to create an image partition of the C: drive. I make new, complete image backups at least 1-2 times per month. Unlike backup of data, which should be done more frequently, these image backups only need to be done when you update or add applications. I don't do that very often.

Finally, if I have a major problem with some software, and think that it may have screwed up other apps, even after it was uninstalled, I simply pull out my image backup, and because I only have to restore this relatively small 10 GB partition (actually only about 6 GB is used for XP and all my programs), I can be back to where I started in less than ten minutes.

As for your initial question, there is absolutely NO WAY I would recommend that you install Vegas 11. I even cringe when I have to use Vegas 10.0e. The only way I would install Vegas 11 is if your video workflow requires you to do all sorts of compositing and use all sorts of effects that take a huge amount of time to render. Then, if you can get GPU rendering to work, what I would do is install some earlier, stable version of Vegas, and also Vegas 11, and create and edit your project in the earlier version, but use Vegas 11 as a rendering engine. However, even doing only that, as I have found out with Vegas 10.0e in the past three weeks, doesn't always work.

I am quite stunned at the amount of problems people are having with V11. I have now completed 3 fairly complex projects with 11 and I have had almost no problems. I did my last project on two different computers, sharing the hard drive and both systems worked perfectly. That project was a 5 camera, 1 hour concert, all HDV footage. My laptop has an ATI graphics card that does take advantage of gpu rendering, which was pleasantly evident, and my desktop has nvidia graphics that also take advantage of gpu processing. I went back and forth with this project with zero issues. I also did a 720p project shot on a Canon 60D DSLR and that too went flawlessly. I also have a copy of Vegas 11 running on another computer that has a much older motherboard with an AMD processor with an older nvidia gpu and on that one I did all my capturing of the above mentioned multicam project footage and synced up all the audio and did some minor edits. Never crashed.

I do empathize with those who are having issues, I've been there before, but I gotta say, V11 (mostly x64, all with windows 7 x64) has been as bulletproof for me as Vegas has always been.

I do have one issue that I have not reported, only happens when I do audio only edits, which I do several times a week. After rendering a timeline to mp3, I cannot play that timeline anymore without closing and reopening the veg. I get an error like the device is not ready, or something to that effect. Slightly irritating and I will report it the next time I get that message so I can get the details right.

One more thing... my systems are pretty lax too, I don't take special care with codecs and software apps etc, I have klite codecs installed on my laptop, tons of apps and plugins, antivirus software running (nod32 v4), I'd be more judicious if I started having problems but...