Our Apaches are different to the American ones.
Very different. Rolls Royce engines develop 30% more power than the US ones. This means that in the heat & altitude of Helmand province, the UK AH's have retained the Longbow MMW radar and have a longer loiter endurance, whereas the US birds have had their radar removed to save weight.
I'd also recommend ED Macy's other book, 'Hellfire' as well as 'Apache'.
For any budding JTACs out there, 'Firestrike 7/9' by Paul 'Bommer' Grahame is worth a go, too