AES in its default block cipher mode can usually be byte-at-a-time decrypted. AES in its "conservative" mode can almost always be byte-at-a-time decrypted when not augmented with another crypto building block that developers invariably forget. When developers don't forget that building block, they often manage to implement it in such a way that it too can by byte-at-a-time broken. AES in its most "modern" mode ends up being exactly as secure as naive XOR when developers use it without understanding its parameters.
On the other hand, if you read the Wikipedia page on Feistel networks and wrote your own --- or if you just used reduced-round FEAL-4 --- but used Keyczar to actually deploy it against real data, all those mistakes I alluded to above would be avoided, and your attackers would have to do real cryptanalysis to attempt to break your application; nobody does that.
Knowing this, you can now see why I'd take issue with the idea that your "Secure Progammer's Pledge" urges people to use "vetted algorithms" to protect data. AES is about as "vetted" as algorithms ever get, and its use in production code by generalist developers is almost always comically insecure.
So: no, that one example turns out not to be more secure than AES, even in Keyczar. The problem is, by itself, it usually turns out not to be less secure either.