Generally speaking, state court is a cesspool. But, I say that lovingly. It's a lot looser and a little more of "anything goes." The "street smart" but not actual smart lawyers prefer to be here. It's far more casual.
On the contrary, in federal court, it can get a little stuffy and self-righteous and sanctimonious. The academics prefer it because they avoid the wild, wild west of the local court. Courts are run strictly. Very little BS. You better be on the ball or you'll get whooped. Shenanigans are not encouraged or tolerated.
As someone mentioned earlier, the jury pool of federal court is slightly more sophisticated. So, if you want more dumb people on the jury (and sometimes you do), state court is a better venue.
If you want to compare it, state court is the local dive and federal court is a 3-star prix fixe restaurant.
Here, Ruiz would prefer to be in Miami state court. He knows all the judges. For better or worse, they know who he is too. And, presuming it would be a jury trial (which is questionable), he'd have more humble folks who'd likely be not as educated.