For small family (3 to 4 members) better u go for it....

Interior  Space Its good for the Front 2 seats, but bit less spacy for the behind 3 seats.

Engine Performance, Fuel Economy Its having a good pickup, may be bit less than your, Eon & wagon-R. Excellent fuel economy, no matter how u handle it ( good for rough drives too).

Ride Quality & Handling Really a good riding comfort for whoever having much experience with small cars. Handling is not much difficult as it's having less turning radius and bit less width...

 Final Words Really a good driving experience with Maruti Suzuki Alto Lx. Even i have driven few, i10, WagonR & Ion, i don't think it makes much difference between these 4 cars in view point of driving, another important thing i want to share is, An "i10" with Power steering  having the same comfort levelin driving ( ease of steering ) of an "Alto without Power steering". but only thing is i10 having bit more pickup than Alto.

Excellent Fuel economy up to 21kmpl in NH. Good riding comfort.Good turning radius.Easy maintainanceBit low space in rear compartment.