Apple,
I've just finished the modular course at OATS.
The main difference with the modular is that you need 150 hours (min) before you can start the Mod course.
On the Intergrated course, after the phase 1 exams, (POF, AGK, Inst, M&B, AP, HP) you then go off to Tyler in Texas for your PPL through to CPL, then back to OATS for phase 2.
On the Modular you dont go to the states so is generally the quicker option.
The Mod guys and gals have the option (at a cost) to then go to Tyler for the CPl then back to OATS for the IR.
So in essence there is no difference, Mod have 150 hours and Intergrated generally dont, thats about it!
Hope this helps
Cheers
TBL