No money up front.
Guarantee of aircraft types to be flown. (at basair as soon as "your type" is unservicable they will have you flying somethin else at your own retraining costs to keep you airbourne)
Your paying for the training. If your instructor is not up to scratch, demand a senior 3, or grade 2 instructor.
Classroom time shouldnt be a consideration. The bookwork isnt that hard and any god instructor should sit down one on one for any issues. These large schools will sit you down all day for self-study anyway.
Stay away from basair.
good luck