Dave Cockle of the Enfield Society has sent information about a slight improvement in the morning peak hours rail service:
Two additional morning peak trains started running from Monday 7th February:
2G01 06:55 Gordon Hill - Moorgate and
2G03 08:23 " " "
Not calling at Hornsey or Haringey.
These trains run ahead of 07:03 and 07:58 Stevenage - Moorgate to avoid overcrowding on what was a half hourly service.
Departure times at Palmers Green are 07:03 and 08:31 respectively.
Note that neither train is shown in the current timetable on the Great Northern website, but both show up when using the online Rail Planner.
A new timetable comes into effect on Monday 21st February. This shows the morning peak service reverting to around four trains an hour, but offpeak frequency will remain two an hour.