HF, I always try give you 170kts (or at least up to 6dme), the lack of requests for 170 to 5 make me wonder if I'm doing the right thing!
Is it beneficial for all 737s at all weights?
maybe the optimum time to make the request is just before you turn base when there's a greater chance you're on the frequency that is going to provide the final approach spacing. But how do you know when that will be?
can't your ops dept speak to our ops dept and make an official request?
would your entire fleet be happy with that?
the only problem we have is, the more we tailor the speeds to suit individual aircraft and airlines, the more complex our job is. That's ok for someone that's been valid for a few years but might be an unnecessary burden on trainees.