I got this for Christmas 2007 with high hopes. But unfortunately it turned out to be a nasty surprise. The level of detail is so low that I wonder if the developers have ever visited the line.
The Class 365 is really horrible because the starting sound is the same as the GNER's Class 91, and when you drive the class 365 it crashes after a few seconds so you have to turn the quantity of sounds down. There are only 10 activities to play, and three of them feature the East coast mainline only and no part of the Hertford loop, and another two of them are only boring Empty Coaching stock workings. There is only one activity that I find fun, that is the King's cross to Stevenage express run with a Class 91.
None of the activities start or finish at Hertford North and there isn't a bridge at the northern end of Hertford North station plus there are extra sidings which do not exist. The only really good thing about this add-on is the Emirates Stadium at Finsbury Park.
Steer clear from this unless you really want the line itself. East Coast Express parts 1, 2 and 3 are much more fun so just get them. Really give this one a miss.