It works beautifully. If you had a longstanding relationship with your Playstation 2 like I did, then you should definitely try this strategy out, because--with some troubleshooting--it will absolutely work on a PC with ideal specs.
Ideal specs would be 4GB RAM, 2-core 3 GHz CPU, a good graphics card (I don't know if I'll ever understand the metrics for graphics cards). I don't think that it even requires too much hard drive space.
Apparently you have to own a PS2 to copy the BIOS files (the basic framework of how the PS2 operates) legally. I do, so thumbs up for me.
Download the emulator.
I used a PS3 controller without a bluetooth dongle. To use a Playstation/Xbox controller that you've connected, download motionjoy and follow their instructions. Make sure to put a shortcut (to DS3 Utility) on the desktop, because you'll probably need to get back to it many times.
SO, this is pretty much what I did that I don't think is in the instructions:
In MotionJoy, for a ps3 controller, I had to wait for Windows to say it successfully installed the driver (I needed to switch the USB port I used), I went to Driver Manager, selected the only controller option that showed up, I reset my computer, and before I wanted to play something, I opened the "DS3 Utility" shortcut, select PS3 Dualshock 3, and hit the pink button "enable" right in the botton left corner. If you don't "enable", windows might forgets the setup sometimes, and the analog buttons don't work when you play.
To get memory cards working, go to CDVD and select "no disc", so you can load to the PS2's main menu. Configure it and everything, go to the browser, and select each memory card and configure them. After that, you want to
To run a game disc, I went to the CDVD menu of the PCSX2 window and selected "plugin", then "plugin menu">"plugin settings">the drive I put my disc into. (I haven't looked into how to use PowerISO or the like to copy the files to my computer and load off of .iso [basically a snapshot of the DVD's image], but I assume it's easy).
EE represents your CPU usage (100% means it's the limiting factor to your speed), GS is graphics card usage. Now, your games will most likely run in slow motion, and the sound will be strange. The sound sucks because it's being held back by the graphics. It seemed to me that all of the configuration options available wouldn't do anything to help my running speed, so I went to "speed hacks" and moved each of the sliders to the right a bit. Play around wiht the other configuration options if you understand what they're saying (I couldn't get most of them, so I left them alone, or guessed at an optimal setting and ended up changing nothing). When I altered those settings to somewhere in the middle, I got Kingdom Hearts and Shadow of the Colossus running beautifully. If your games start to strangely run incredibly fast, then make sure you have the "disable framelimiting" option in the GS tab UNchecked, so that the emulator DOES frame limit. (this means the speed at which your graphics card creates images, measured in frames per second, will not exceed the intended running speed)
If you have any questions, drop a comment. I had to do a lot of troubleshooting, so I got pretty familiar with the interface. I'm not as good as google, but I am at least better than a first-level computer maintenance person you might call for troubleshooting at 3am; then again, aren't we all?