All part of the friendly (?) Anglia Railways v First Great Eastern competition. Another nightmare was the revenue raiding Basinstoke service, that always seemed to get in the way too. The highlight of that campaign was when FGE took over the Station Hotel pub opposite Ipswich station one evening with a big blue and green banner advertising cheaper tickets to London. Caused a bit of a stir to put it mildly.
Moving on to the National Express era, the bid they put in for 170s to Liverpool St was awful and needed a lot of work to knock it into some sort of shape, but it was never going to solve the fundamental issue that a 3 car 170 to Liverpool St is ridiculous for passenger capacity. The saving grace was winning the 2012 Olympic bid. That allowed an operational led timetable that could be strengthened to 12 cars on all GEML destinations if necessary. This too was done under NX in Dec 2010, as was the improved Dec 2011 West Anglia timetable, so they weren’t all bad, unless they had to spend any money.
Bringing all this up to date the through Lowestoft trains are a dilemma too. Too short and you won’t be able to stop many places, but adding and subtracting coaches at Ipswich (or Colchester) isn’t attractive either. Lots of water to go under the bridge until a settled GEML timetable is arrived at.