The only place I can think of where speed control is continually used to provide separation is within the London TMA and that is simply because of the sheer volume of traffic that flies into and out of the London Airports.
As an approach controller at a reasonably busy airfield I and the majority of my colleagues would prefer to vector rather than apply speed control, when it's not so busy, it makes more sense for us to provide you with vertical / horizontal separation and let you do your own thing with the speed. We tend to find that this works fine in 99% of approach sequences as we have an appreciation of the a/c performance and particular airframe speed limitations at lower levels (E145 as an example), I would only use positive speed control during a sequence of 5 or more successive and closely spaced IFR arrivals.
As for co-ordination, when a/c are handed over to me by Scottish, they are usually above FL100, inbound to the hold, or on a radar heading to separate from other traffic. It is then up to me to decide the position in the sequence of each a/c when they call me and also if it is necessary to apply any speed control.