So I installed the 160 GB Maxtor drive into my PS2 (formatted to 152), and booted up the HD loader. Started fine, so I decided to "test" it with a copy of Killzone... it took 30 minutes to rip the game, and I had to put it into "Mode 3" for it to run. Worked fine, and the only real difference between the disk and HD versions was that the HD copy had an insanely fast loadtime.
It's just sad because I went from playing Halo 2 (beautiful) to Killzone (beautiful for the PS2, dirty looking in comparison to Halo

h: ), but now I'm freed from the tyranny of DVDs, so I'm happy