Well, I'm probably biased because my regular group is usually between 8 and 10 players, all with high level characters. Add in animal companions, cohorts, and summoned monsters, and I need every single bit of help I can find in managing information during even a relatively simple encounter.
I don't think the problem with the old statblock was so much that people couldn't fiind the information at all, as in, "Duh, I know this thing has damage reduction, but where is it listed, ???????" but that they couldn't find useful information quickly, as in "OK, the monster gestures at you and a black cone of energy shoots from one of its tenacles. The cone strikes, uh, let's see . . . uh . . . no . . . oh, OK . . . it strikes Timon and . . . uh . . . oh, there IS a save . . . you need to make a Saving Throw, Timon . . . uh . . . Reflex . . . let me see . . . the DC should be . . . [calculating silently]"
The new statblock is designed to present information more-or-less in the order you need it or in the order of importance.You start at the top and work your way down. Does the monster see the PCs? OK, there's the notice skills, right at the top of the statblock. If the encounter starts, what's its Init modifier? If the PCs want to talk, can it respond? And so on.
Putting things like DCs, attack bonuses, or brief effect summaries up in the stat lines (like "Special Atk poison (DC 14, 1d4 Str/1d2 Str)") makes it easier to grab these little details in the midst of melee. I find just bolding the stat block headings makes it much easier to quickly put my finger on what I need.
But to me, the biggest problem with the old statblock format wasn't that I couldn't find info I knew was there . . . it was missing important things that I didn't remember and were buried deep in that big ole blob of text. I couldn't tell you how many encounters I have run where afterwards I realized I had forgotten something like spell resistance or energy resistance or an important immunity, even though it was sitting right there in my old format statblock.
I've found that, espeically with high-level or complex monsters, the new statblock format does a great job of "reminding" me of those little abilities that otherwise got forgotten in the heat of a massive melee.