It was a slow find near Asheville NC, but the Tumbler has finally popped up somewhere I could grab a copy. The Batman Begins suit might just be one of the most subtle updated designs I've seen in a DC minifigure. There are slightly fewer lines for detailing (with the exception of little "points" near the neck where the movie's cape attached, nice touch), which definitely gives it a smoother look more befitting the film. The belt is the most noticeable change. The old version is more intricately detailed, and much thinner; it's probably more proportional to the movie, but I like the newer one looking more in line with belt sizes on other Lego Batmen. The back is quite obviously different, but won't really matter too much for most people.
The big downside is switching back to the "standard" Batman face instead of the unique head the last one has. I legitimately hate that Lego never used that face again, as both sides not only work better for a "serious" Batman than the cocky grin, but the old face's printing looks so simple and cartoonish in comparison now. I finally caved and ordered a handful of those on bricklink for my main display figures.
And of course, the fear gas face is A+, but literally everybody already knows that.
Now if someone would just actually put The Batman sets on shelves, I will be a happy man. Literally every local Walmart and Target I have checked has been so slow to stock any Lego it's insulting.