It's A4 sized now and only slightly thinner than before when it was about 1/3 of A4 size. I suppose the expansion into southern Schleswig-Holstein and the resulting increase in number of bus lines made that difference.
Also, the map is now no longer a folding map that comes with every other timetable but is instead a set of pages at the back, similar to maps you sometimes see in the Yellow Pages or something.
I find that not so good. You can't see the whole thing at once, for one thing.
Also, the map isn't very comprehensive. It's in three sections, with successively larger scales: central Hamburg, greater Hamburg, and the entire area.
However, the central Hamburg and greater Hamburg sections appear to be limited to the information that used to be on both sides of the previous map. Specifically, new bus lines that aren't part of the old numbering scheme aren't shown on it at all (for example, busses in Elmshorn and Tornesch, or the 900 express bus from Ratzeburg and Mölln to Wandsbek-Markt), and bits around the eastern and southern border are cut off.
And on the largest-scale map, there are only relatively few HVV busses marked -- Hamburg itself is not depicted, except for the outskirts (so there's a kind of "hole" in the middle of the area covered by the largest-scale map pages), and in the bits served by HVV busses, only the "Metrobus" lines are marked. So even though the medium-scale maps say "continued on page X", the "normal" bus lines aren't actually continued. Bummer.
Oh, and the grid lines still have the numbering system introduced a couple of maps ago, with numbers on both the X and Y axes, which I consider error-prone. Before that, it was letters along the X axis and numbers along the Y axis, which gave coordinates such as "Q16", which I think looks nicer than the "16/21" they have now.