hi,
first of all, if april is too late for you think again. If you still need to go through the selection process with L3, the earliest you can start is probably February or so. which is only a 2 months difference.
I personally think that the choice for a flight school should be made on your personal experience during the open day and the feeling you have with the instructors, company structure, location etc. During the flight training there is a lot going on and you need to be able to focus yourself on the training.
Don't change your mind over maybe a 2 months earlier start. Use those 2 months to prepare yourself with maths and read through the ATPL books.
FTE is a great school, so is L3. You really have to make the decision based on your feeling with both flight schools. At the moment FTE seems to have a slight edge in terms of airline placement since the AQC holdpool at L3 is piling up due to Easyjet not hiring from them at the moment. I am sure that will be resolved by the time you finish your training with L3.
L3 does have very good and professional instructors during ground school as well as the flight training.
9k GBP for AQC? Are you referring to integrated or modular training with both schools? If you go fully integrated with L3 the AQC is included. After completion of AQC they will place you in the holding pool and they will try and get you an interview with one of their partner airlines. They will look into your overall performance during the flight training to see if you are suitable for a particular airline. Think about the maximum amount of groundschool fails, avarage, first series passes CPL and IR and solid performance throughout AQC.
As I said earlier. Think again. Make your decision based on what you think. Flight school preference is very personal and as you said FTE might be a little bit more familial. If that is important to you, go for FTE!