This is a good add-on. The graphics are good, the stations are very detailed, the rolling stock is really excellent, the starting sounds of the GNER Class 91 and 43 are very very realistic, the same goes to the Class 220 Voyager. Signals can be seen a long way off.
My only criticism would be to say that there should be some extra trains in stations, sidings and loops, people on the platform waiting for your train instead of seeing a deserted platform when approaching a station, and in some locations where fast points should be placed there are quite sharp slow crossovers, so hitting these at high speed and crossing over would not be realistic at all.
Other than that the add-on is very good fun to play, if you have the East Coast Express Part 1 installed the two add-ons will link together creating one long route, and there are even activities that go all the way from York to London! But even if you don't have Part 1 there are still 12 activities to play, which are excellent.
On the whole it's a good add-on and I can recommend it.