Last I heard EMA are not too enamoured with Parkway, as the number of trains EM Trains have scheduled to call there is not huge.
There are 3 trains/hr to Leicester (2 go on to London) but they all run within 12 minutes of each other (32/39/43 past the hour)and then there is a large gap. There are 2/hr to Nottingham very close together (46 and 57 past the hour) and one/hour to Derby (53 past the hour).
So nothing for the first half of the hour - plenty of time for the station staff to keep the premises in pristine condition .......
Lets hope the connecting bus from the airport is not timed to get there on the hour
Suzeman