Better, but still not great. In general, I would say avoid the 7200.11s.
Part of the reason it's difficult to completely classify the 7200.11 reliability as well is that the "7200.11" is actually two complete generations of drives. Initially, the 7200.11 was known internally as "Moose", with 250GB per disk and capacities up to 1TB. These had abysmal failure rates, and were in general terrible drives. Later, around Summer 2008, "Brinks" was released, still under the name 7200.11, with 333GB (or so) per disk, and capacities up to 1.5TB. This was slightly better, but still had some odd reliability problems. Given how cheap a 7200.12 is, I would say that it's always worth buying the newer drive if you need a new drive, and if you have an older 7200.11 that is still working, you can keep using it, but I'd say backups are a good idea (of course, backups are always a good idea).