The issue is simple: Why buy Terminator 2: Judgment Day Extreme DVD, the THIRD pressing of James Cameron's hit -- an overtly mercenary attempt to cash in on ''T3'' -- if you've already got 2000's Ultimate Edition? The answer is, unless you're the most desperate kind of cinema geek, you shouldn't. The Ultimate Edition had the supplemental mother lode, as well as the same 16 minutes of reincorporated footage you get with Extreme, while here the big bonus is a commentary track from Cameron (his first) and his cowriter, William Wisher. To be fair, the commentary is a great one: funny, breezy, and informative (it also makes you wish Cameron would get his head out of the water and make another friggin' movie). But it's not worth spending the $29.98 to own. Rent, baby, rent.