The difference with going integrated is:
-SOPs from the start
-the monitoring of training and continuous progress tests prevents bad habits and bad habits are hard (and expensive) to break.
-structure and progression from the start.
-The use of things like AIPs and Tech Logs which I am sure alot of Modular people who go and hire a 152 in Florida do not use properly or even touch.
- All the bits in between the licences and ratings.
-Continuity of instructors.
-A final report which is almost like an indemnity to the airline should anything go wrong in their training with the airline.
However if you do a PPL, ATPLs, and then join a proper modular course like OAA, FTE, BCFT, PAT etc. then there isn't really any difference apart from the cost.