The whole issue here is the implied consent, not having judges on site (which is what people here seem to be flipping out over).
These work like a normal DUI checkpoint. Most people have been through them. They have the road blocked, you drive up, they ask for you license. When you hand it to them they smell your breath and the car and shine a flashlight into your eyes to see how they dilate. If any of those offer probably cause they ask you to pull over and go through a sobriety check. Failing that they generally give a breathalyzer test and failing that you get arrested. You, through the fifth amendment, have a right to voluntarily refuse. They, through how our legal system work, then have a right to request a judge review the case and issue a warrant, usually for a blood test as you have no physical control of that (no warrant could make you blow through the tube hard). All of that is perfectly legal and has been since the US was first founded and, IMO is just fine.
Now, people who drive drunk often have tricks, most do not work. One of them that might maybe work is to simply refuse everything and wait for a judge to be consulted, review the case, issue the warrant, get a medical technician down there, and draw blood. A process that can even take a couple of hours on busy nights. During that time you metabolize alcohol and have a chance to fall below the legal limit, especially if you were barely over the limit to begin with.
The *only* difference is that the Judge and medical worker are on site. If, as stated in some of these articles Florida has some "implied consent" then the issue is there, not with this type of checkpoint. They could have a drunk tank collect up people, drive the to the county building, issue the warrants, and take blood already on the simple refusal. This isn't a change in law or a change in practice, it is a change in the amount of time needed. They make the argument (and again, this part is *not* new by any means) that by accepting your drivers license that you have already pre-agreed to take a breathalyzer test any time, anywhere, and for any reason. Not really sure though why you can't suddenly decide that to not be the case as you can certainly decide in a question by question case to exercise your fifth amendment rights, further the fourth amendment isn't a tiny one either and is fairly explicit about refusal not being evidence for a warrant. Obviously given the amount of time this has been in effect it either hasn't been challenged or has and some crazy judge found it constitutional. I suspect that a constitutional fight against an "implied consent" would win (but, as we have seen with our current courts the constitution is seen as a "living document" where the bigger question is can you rationalize it to say what you want it too so who knows), I suspect they know that, and like many other crappy laws they only enforce in places that they know they would not loose.
As for the Judge on site, many other states do them and its a pretty good idea. In most states they can't detain for refusal of the breathalyzer unless they have fairly strong probable cause - basically if they would have detained you and gotten blood before they still can. If the police have probable cause to require testing and given that the most accurate gathering of facts will occur this way it is quite within the intents of our judiciary system to do this. Further with the Judge on site they can personally oversee the idea of probable cause and the treatment of the detainees by the police. Lastly it certainly works well on the whole "speedy justice system". For everyone but the person that is only slightly over the legal limit who would have gotten away with it this is a win. There isn't a constitutional argument that it is his right for a slow gathering of facts simply because that would favor them.
I would bet Florida is on shaky grounds with it not because of the judge on site, but because implied consent is, well, stupid. Having a Judge on site is a pretty good idea IMO.