As I noted previously, I did get Parallels 8 installed on my MacBook Pro. The culprit was my Wacom Intuous5 touch tablet. They did have a hot fix for it I was able to download and install. Voila! Success!
If you have used Parallels for a while, there aren’t that many features at the user level to get excited about. Their What’s New page boils it down to three things: ease of use; Retina display support; and performance, especially battery life. I expect most of the improvement is under-the-hood in making it Mountain Lion– and Windows 8-compatible. Unlike most users, I primarily use Windows just for Internet Explorer. My employer allows remote access from machines running IE. They download a couple of Java apps to check the configuration (e.g., important patches, virus software, etc) and one to scrub the cache when you are done with your session. Microsoft’s RDC runs in the browser so you are looking at your desktop at work.
I have used Parallels since version 3 and there is one annoying bug they have never fixed. From time to time the VM takes 100% of all the CPUs allocated to it. I usually notice it when I am running Remote Desktop in the browser. When that happens, you have to shutdown the VM and sometimes Parallels itself to get the CPUs back. Every release I keep hoping it will be fixed and no luck. Could just be a quirk in Windows because I have not seen it with any other hosted OS.
I installed vmware’s Fusion 5 just for the heck of it. For the most part, I think I like it. I have been using it for all my "work" sessions and so far, so good. A couple of quirks (yes, it’s the word of the day) I noticed. The first is the devices Window’s can’t find drivers for – like the display. The display works just fine, Window’s just can’t find a driver for it and I haven’t figured out how to tell it to stop trying. One thing about the display though: it would appear that it can’t use a "non-standard" resolution. On my Cinema Display HD, I can’t get the Window’s window to use the full screen; it has to be a ratio of something standard. Parallel’s doesn’t care how you shape the window.
The second quirk has to do with how the VM handles mouse and keyboard input. In Parallels, when your mouse is over the VM (I run in a single windowed mode) the VM catches most of the keystrokes. Some, like a Ctrl-arrow that moves you from desktop to desktop in OS X, aren’t caught by the VM. Instead they are passed directly to OS X. In vmware, the VM catches the keystrokes, so a Ctrl-arrow will do a jump to next word in Microsoft Word. And Cmd-Tab won’t work but Alt-Tab does switch apps. To get it to behave like I want, I have to move the mouse out of the window so it is "out of view" of the VM. Then it behaves the way I want. Not a big deal but it will take some getting used to I think.
One thing I don’t like is the Full Screen mode. It is what it advertises: it takes the entire screen for use by the hosted OS, including the tool bar right up at the top of the screen. Maybe there is some key combination to get it out of Full Screen mode but the only way I’ve found so far is via the View menu. But to get to the view menu, you have to get to menu bar. I think when your mouse bumps into the top of the display it drops down but I can’t do it every time so it may be something I don’t realize I’m doing. In any case, I use the Single Window mode and it works just fine.
Fusion 5 is vmware’s latest release so of course it’s Mountain Lion- and Windows 8-compliant, leverages Retina on the newest Macs, runs faster, jumps farther on less battery power, etc. According to vmware, it’s got 70+ new features. Not sure how many "+" is but they are there.
Am I going to buy Fusion 5? I don’t know. I haven’t used it enough to have a solid opinion of what Fusion has that Parallels doesn’t. If you are considering a switch, they offer a 50% discount as a carrot if you already have Parallels