I used Karwa (Industrial Area) while my wife used Modern Driving School (near Aspire). Both I found very good.
Karwa:
+ Has a theory class, professional front desk, good instructor (manner and English)
- Far, traffic is not favorable

Modern:
+ Access, good instructor
- No theoretical class, front desk is not well equipped with good english

Doha Driving School
I visited twice for registering my wife but don't like the attitude of its front desk hence canceled the registration

Many schools require candidate to take 12 hours minimum. Tough in my case I took only 7 hrs.