I am trying to decide between the Plextor 12x10x32 or the Plextor 8x4x32. Is the speed between them that different? Is it worth spending an extra $60 to get the faster one?
No, the extra speed isn't worth it, but the BURN-proof technology on the 12x model is. The 12x with BURN-proof will pause writing when it runs out of data and continue when it gets more data, but the regular 8x model just stops burning all together, thereby making you a coaster. You can even use your computer while burning in the background with the 12x, which is somehting you could never do with a regular burner. The 12x model with BURN-proof is worth the extra money.
I've got a TDK 12x10x32 (which is a rebadged Plextor) You can defintely notice the speed difference between a 12x and an 8x. But the biggest factor by far is the Burn Proof. As a bonus, TDK just released a 16x10x32 so the 12x came down in price. Get em' while you can.