99% of the spyware/viruses that I could acquire while on my PC have no effect on my Mac.
That's because you don't know how to use Windows without an admin account (like most housewives and teenagers), which pretty much makes windows as immune from that crap as OSX. You otherwise have my encouragement to go Mac so we have one less Windows user to baby sit and rant on about Spyware removers and how 'awesum' Apple is.
went into a MAC store for the first time a few weeks ago and opening up several programs at once,
Wow, when did you stop using Windows 3.11?
I haven't used the new PowerMac, but I have worked on Dual G5's, and frankly didn't find OSX on that platform more/less responsive than a 3ghz+ P4. If anything, I found my own custom built dual Core Athlon machines a bit snappier than the dual Apple G5 - except for Photoshop which screamed on the G5 because of Altivec. My conclusion here is you are so used to Windows machines bogged down with garbage, useless security programs and trojans from pirated software you think OSX is faster. Please look up 'PEBKAC' on Wikipedia for a technical explanation of this.
The Mac Pro is based on a Intel Dual Xeon motherboard that if you do some research you can find pretty much the same beast at Supermicro.Com or inside a Dell Precision, minus of course the Apple BIOS allowing OSX to be run on it. There is otherwise nothing special or unique from a hardware perspective about Mac Pro compared to any dual Xeon Intel based workstation. It's an Intel clone in an Apple case and a whole lotta marketing - so deal with it.
You could build your own dual Xeon with te same specs as the Mac Pro, but it wouldn't be much cheaper. However, this is just a lunatic pursuit because as iMac users are starting to grumble about in Apple forums the Mac Pro is not an ideal machine in terms of price/performance. Four cores can't do more work that two cores at the same clock unless you're using a one of a handfull of apps spawing simplistic threads that can utilize the extra cores. however, I'm sure the dude in the Apple store didn't tell you that. In fact, a single processor 2.66 Core 2 Duo machine would perform identically to a 2.66ghz Mac Pro expect for those few tasks. The difference in price however would be dramatic.
So, the problem is if you want to run OSX (the only arguable reason to buy a Mac), is you're forced between an Apple Notebook, iMac (a desktop LCD built on a laptop chassis and not very expandable), or the inefficient and expensive Mac Pro.
True it may be faster, but I remember someone telling me (or did I read it somewhere?) that if you kept a PC and a MAC on for 24hrs not doing anything.
I'm sure you read this on Apple.Com as well. Feel free to google the top 10 web/application hosts in your area offering 24/7 service and find how many of them are running OSX vs Windows. Some of the Windows Citrix boxes I've installed and supported run upwards of 50 simultaneous applications, yet the only time I reboot them is to install or update apps every couple of weeks - going back to NT 4. To be honest, when I hear comments like that I no longer have sympathy for U.S. tech jobs going over seas that's for sure.