Big Als,
Im currently with GTS on the ATPL course. The guys there are excellent and always happy to help and provide support, and you can drop in at any time and they always have time for you.
However..... the notes...
The notes are comprehensive in the extreme if im honest. Getting through them is like trying to run through chest high water! To provide an example, I went to the Flyer exhibition in Nov and nearly fell over when I saw Bristols and even the Jepp manuals. Bristol have all 14 subjets covered in the 7 folders, two subjects per folder! GTS have 14 folders! and the content (sheer amount of material to get through) of one subject in one folder, practically totals two of Bristols subjects in single folder.
Bristols notes are designed to get you through the exams, what you need to know, plain and simple. They are colour too.
To sum up, if you want an encyclopedia of ATPLS choose GTS. If just want the material to get you through the exams (most of us do!!) choose bristol.
Ill say it again though, cant fault the GTS service and support. cheers
Expedite