Roshan,
I like your review, it's honest and objective.
I agree with everything you said and personally feel that this is a quality machine designed for a specific purpose. While you could correct the paint on an entire car with this small machine it simply wasn't designed for such large areas.
Slower speeds are more suitable for applying sealants and waxes but not for correcting. When you get nearer to the higher end of the speed range you'll actually see and feel the pad rotating so this is a perfect speed for surgical correcting or possibly wet-sanding.
Great job buddy! :bigups