RevStar,
A few observations. I have no problem at all with visual approaches, BUT when the aircraft in question are operating under IFR, responsibility for separation, (in the UK anyway), still rests with ATC. It is easy to maintain a full picture, but some degree of control is lost when a pilot decides to go too far downwind and the sequence is adversely affected. There should be no associated safety issues; successive visual approaches are conducted subject to following only one aircraft ahead, so correct identification should not be a problem.
Visual approaches being more efficient than radar vectoring? I don't think so! Would pilots be happy to sequence themselves 2.5 miles apart on final approach? I think not. And how would they know what speeds the aircraft ahead are flying to be able to maintain separation acccurately? Would pilots know the appropriate vortex wake categories and spacing requirements? What is the difference between an instruction and a clearance in this context?
Would flight crew really want to take on the spacing responsibility after a long haul flight? Is their workload not high enough in the approach phase? And you would be reducing ATC to merely a monitoring function - is this wise?
There is no doubt in my mind that these proposals would impact significantly on capacity issues. What is the driver behind their introduction?