Listen - the difference between Cranfield and Guildhall modular courses is negligible. I know people at Cranfield and apart from the slight difference in feedback question quality there is little to choose between the two! Cranfield is slightly better on that front but Guildhall will try and teach you the whole JAR syllabus therefore hopefully making up for this slight disadvantage. Guildhall is quite a bit cheaper too and the lecturers are generally good. If you live locally I would recommend Guildhall.
NB. My advice is good for the modular course but doesn't quite apply to the integrated course at Cranfield (although I do know people at Cranfield on that too!).
Whatever you choose good luck!