ATC recognizes this and understands the fact that on some aircraft gear and flaps would have to be extended to maintain 160 knots on the nose, resulting in a larger noise foot print to those on the ground.
Yep, I know that. But I have been told off by ATC before when their mode S readout showed I hadn't bugged 160k. In addition, the auto throttle in the Boeing has a tendency to fly on the fast side. This is due to the way the A/T logic works. Selecting 165 often results in the A/C flying around 170 kts.
170 to 5 gets around all of this just nicely.
not a show stopper for traffic separation with traffic 4 to 5 miles ahead flying 4 knots slower
Except that the traffic ahead is not flying at 160 kts any more, since they have slowed down to their final approach speed. If their final approach speed is 115 kts (and they started configuring early to get the speed off, as seems to be required on a light -700 according to earlier posters) and mine is 145 kts, that 10 kts extra speed to 4nm might just become a factor.
'continue approach, expect late landing clearance'