^^ nope, everyone's talking about DA w/o antenna cables.
Honestly, you have ultegra, you've admitted that you don't have tons of cash kicking around -- is it worth $600 to you to upgrade? Are you going to race? what happens if you crash? If you don't race, do you think it'll make much difference at all to be riding DA? If you just want the feel, ultegra SL brifers go for <$200 on ebay, and have nearly the same metallic click that DA does.
It's all up to you, but upgrading just because you can concievably do it in your budget doesn't always make it a good idea