Back in the early days, Universal commonly released two versions of a film on DVD, one with a DD track and some extras, and one with a DTS track and little to no extras. For example, Jurassic Park and 12 Monkeys. Lately, with releases like Fast and the Furious and Meet the Parents, just to name a couple, they've been putting a DTS track and tons of extras, including commentaries, onto the same size disc. What I want to know is, what led to this change? Was it a policy change on Universal's part or did advancements in authoring techniques allow them to fit more stuff on one DVD-9?