I know several people (myself included) who bring meat and other food from the US often. Ive had my cooler opened and they never "confiscated" anything.
I, for one, bring back certain "comfort" items when I return here because I miss them and there is nowhere close (if at all) to find them. As for beef, because no one dry ages beef here (at least to my knowledge), you're only choice is imported, frozen angus, omaha, etc...so why not just bring it yourself?
As for burgers, Ive found that buying the cheaper ground beef (with at least 20% fat content) tastes much better than the prime stuff here...and pretty much like ground chuck or even ground round from the US. The regular ground beef here has less than 10% fat content - like ground sirloin in the US, but because of this has very little flavor, dries out easily, and has an odd texture when cooked.
if you do decide to bring frozen foods...make sure they're VERY frozen and packed as tightly as possible in a good cooler. I usually have one or two of theose blue gel frozen ice packs in there as well. And unless you add some dry ice, it will probably be starting to thaw by the time you arrive in the DR...