This route is good for both the casual and aggressive rider. Corner visibility is a mix of about 50-50 open and closed but decent enough when all is said and done to give you the confidence to lean into them. There are varied corners ranging from long, sweeping, fast to tighter corners to keep interest up.
Various sections of the route have had repairs done, e.g. resurfacing etc, but they tend to be quite patchy and there are still some areas and corners where caution is advised. I generally found it to be decent though and was confident enough to be quite aggressive in the corners. More competent supersport riders and the likes should have no troubles. If it's a wet day you might want to take it easy....
The straights are sufficient in length to build up some serious speed, but don't expect to be hitting IOM TT speeds any time soon! Also, traffic on the weekends will generally prevent you from getting too excessive on the speed front, but it is still enjoyable. Best bet for the more aggressive rider is to go late mornings on weekdays. The main A21 heading south out of Tonbridge (a good place to full up with petrol and use as your starting point) can be used to get some heat into the rubber for when you reach the country roads and you want grip from the start into the twisties.
When it comes to police presence I have personally only seen one or two around in cars before. There are speed camera signs when you get into and near the villages etc along the route; but having ridden/driven these roads many times have yet to find a fixed one if memory serves. As always I would advise you keep your eyes peeled, just in case... Most likely place to come across police I think are in Tenterden and going through Hawkhurst as well as the A21 sections.
Along the route the villages (e.g. Tenterden, Hawkhurst) do have various pubs etc that are good to stop and take a break at and grab food; and there are also small petrol stations dotted alond the route when you're running low.
All in all a decent little loop I think.